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The objective of this study was twofold. (1) To investigate the predictive characteristics of transvaginal ultrasonography for hysteroscopy necessity in Essure removal surgery. (2) To investigate the additional predictive value of a preoperative pelvic radiograph to transvaginal ultrasonography for hysteroscopy necessity. Retrospective cohort study, performed in an academic and a non-academic teaching hospital in the Netherlands. 71 women who underwent Essure removal surgery with a perioperative hysteroscopy and who had a preoperative pelvic X-ray and transvaginal ultrasound were included. Four experts first predicted hysteroscopy necessity based on transvaginal ultrasound description and secondly based on transvaginal ultrasound combined with the preoperative pelvic radiograph. Sensitivity, specificity, positive predictive value and negative predictive value of the predictive tests were calculated. Based on transvaginal ultrasound, the mean predictive characteristics for experts were: sensitivity 89.7% (range 66.7%–100%), specificity 37.4% (range 17.6%–67.7%), positive predictive value 18.8% (range 13.2%–29.5%) and negative predictive value 95.1% (range 86.1%–100%). After adding the pelvic radiograph to the transvaginal ultrasound descriptions, the results were: sensitivity 66.7% (range 53.3%–80%), specificity 72.6% (range 56%–97.3%), positive predictive value 23% (range 14.3%–26.9%) and negative predictive value 94.1 % (range 90.3%–98.4%). For three experts sensitivity decreased after adding the pelvic radiograph. For all experts specificity increased. It is difficult to preoperatively decide if the fourth marker of the Essure outer coil can be excised during hysteroscopy. The addition of pelvic radiography to transvaginal ultrasound is not beneficial. It is recommended to perform a hysteroscopy during Essure removal surgery. [ABSTRACT FROM AUTHOR]

Background: There is widespread variation in the optimal procedure for correction of severe hallux valgus deformity defined as hallux valgus angle (HVA) (≥40°) and/or 1-2 intermetatarsal angle (IMA) (≥20°). There is limited evidence investigating the clinical or radiological outcomes following treatment of severe hallux valgus deformity with third-generation minimally invasive chevron and Akin osteotomies (MICA).Methods: This was a prospective observational single surgeon series of consecutive patients who underwent primary third-generation MICA with screw fixation for severe hallux valgus. The primary outcome was a validated patient reported outcome measure (PROM), the Manchester-Oxford Foot Questionnaire (MOXFQ), assessed minimum 2 years following MICA. Secondary outcomes were radiographic deformity correction (assessed 6 weeks post-operatively), complication rates and other quality of life PROMs (EQ-5D and Visual Analogue Pain Scale).Results: Between September 2014 and November 2018, 106 consecutive feet (n = 78 patients; 73 female, 5 male) met the inclusion criteria. Prospectively collected pre-operative and 2 year PROM MOXFQ data was available for 86 feet (81.1%). At two years following surgery, the MOXFQ score significantly improved for the Pain, Walking and Standing and Social Interaction domains from 39.2 to 7.5, 38.2 to 5.9 and 48.6 to 5.5, respectively (p < 0.001). Pre- and 6 week post-operative radiographic data was available for all 106 feet. Mean IMA improved from 18.2° to 6.3° (p < 0.001) whilst mean HVA improved from 45.3° to 10.9° (p < 0.001). The complication rate was 18.8% and the screw removal rate was 5.6%.Conclusion: This study has demonstrated third-generation MICA for the treatment of severe hallux valgus deformity enables substantial deformity correction and is associated with significant improvements in clinical PROMs 2 years following surgery. [ABSTRACT FROM AUTHOR]

Capillary infiltration is an innovative fabrication method for metal and ceramic-matrix composites. SiC/SiC composites can be infiltrated by molten silicon to decrease residual porosity. Physical and chemical mechanisms involved during Liquid Silicon Infiltration (LSI) are complex to analyse. An in situ observation setup for capillary infiltration of molten silicon has been designed for synchrotron observations. The setup reproduces the extreme high temperature and high vacuum conditions used in the LSI process. It is also designed for X-ray observations in synchrotron beamlines and tomography stages. Sets of 2D X-ray absorption radiographs were acquired at high frequency during the LSI process. The study outlines the capillary infiltration mechanisms of molten silicon inside SiC/SiC composites. It proves that full saturation of the composite is not directly achieved after the rise of molten silicon. It is a two step mechanism. First, the infiltration occurs inside the intra granular porosity of the SiC powder matrix. Then, larger scale porosities such as cracks are filled. These phenomena have been discussed previously in the literature but never observed in situ. [ABSTRACT FROM AUTHOR]

Clay materials such as montmorillonite-rich bentonite, are planned to be used as buffer materials between waste canisters and host rock in deep geological radioactive waste repositories. To ensure the safety of the repository over very long time scales, it is essential to understand the mechanical and transport properties of the clay materials through measurements and modelling. Here, an experimental method based on X-ray radiography was used to gather temporal data on the hydro-mechanical behaviour and homogenisation of three bentonites with different initial dry densities and wetting solution chemistry. The results showed that the salinity of wetting solution and the dominant cation of montmorillonite affect the overall saturation and swelling process of the clay material thus indicating that there is a chemical coupling to the hydro-mechanical behaviour of montmorillonite-rich clay materials. In particular, higher salinity was associated with more rapid wetting and a more homogeneous distribution of bentonite material in the final state of the experiments. The results also highlighted that the new measurement method is much faster and less cumbersome than traditional gravimetric methods. The method yielded detailed data on the wetting and swelling processes, and may thus help obtain better insight on the intricate hydro-mechanical properties of clay materials. • X-ray radiography enables monitoring of wetting, swelling, and homogenisation in bentonites. • Increased wetting liquid salinity accelerated homogenisation and swelling rates in bentonites. • Heterogeneities persisted post-experiment across all samples. • Detailed time series data supports safety case modelling for radioactive waste repository concepts. [ABSTRACT FROM AUTHOR]

Backscatter radiography, a form of x-ray inspection, has been used for better detection of flaws and degradation in the inspection of crossties. The method utilizes the portion of photons that scatter off the target object back towards the source. Current systems detect flaws and degradation in wood crossties but have been limited to the area of the tie between the rails. To advance the technology, this investigation seeks to evaluate the portion of the tie underneath the tie plate where x-ray attenuation severely impacts the image quality and penetration depth of the photons. Laboratory experiments were conducted to simulate scanning through tie plate materials. Scanning through the tie plate material is the best-case scenario for adapting current practices. Results show that backscatter radiography is an effective non-destructive testing method for crosstie evaluation and scanning through a tie plate is possible, but limitations exist with regards to fidelity and image resolution. [ABSTRACT FROM AUTHOR]

• For the first time, ZrO 2 t-m bands were observed under tension in Ce-TZP composites. • Microscopy and ex-situ SXRR showed that bands formed at 90° to the tensile axis. • SXRR provides a relevant information from the entire volume of the sample. • Transformation bands can be imaged by SXRR through the X-ray transmission signal. • The peak position of the refraction signal enables much more precise imaging. The stress-induced tetragonal to monoclinic (t-m) zirconia phase transformation can provide a certain degree of plasticity to Ceria-stabilized (Ce-TZP) zirconia-based composites. Characterizing and monitoring this phase transition on a millimeter-size range, within the bulk and in-situ remains a challenge. In this work, the mechanical behavior of Ce-TZP based composite was studied in tension, combining microscopy and synchrotron X-ray refraction techniques. In contrast with microscopy methods, which only provide surface information, X-ray refraction radiography (SXRR) allowed the visualization of all the transformation bands, over the entire length and thickness of tested specimens, opening up new avenues for in-situ stress-induced t-m transformation studies. [ABSTRACT FROM AUTHOR]

The X-ray spectrum changes while traveling through specimen, and this phenomenon, known as the beam-hardening effect, breaks the linear relationship between the intensity variety on radiographs and material thickness. In the detection of water transport in cement-based materials, this effect leads to inaccurate results of the quantitative moisture distribution inside the sample, and it is difficult to eliminate this effect by gravimetric calibration. To solve this problem, this paper proposed a calibration strategy for the attenuation coefficient curve of cement-water two-phase specimens, and provided a heuristic mathematical model for fitting the 2D attenuation coefficient surface of cement paste specimens. The experiments showed that for zones close to saturation, beam-hardening leads to an overestimation of moisture content, while for a zone with a low water content, the X-ray radiography results without correction tend to underestimate it. After correction, the method showed a quantitative result close to that of the gravimetric method, and maintained a good stability in samples of different thickness. • An X-ray beam-hardening correction method for quantitying moisutre content in cement paste was proposed. • The effective attenuation coefficient in two-phase materials comprising water and cement has been obtained. • The quantitative error due to beam-hardening effect was reduced from 26.9% to less than 5.65%. [ABSTRACT FROM AUTHOR]

• Localized dynamic penetration of closed cell aluminum foam. • Dynamic instrumented penetration using direct impact split Hopkinson bar. • Visualisation of deformation processes using flash X-ray system. • In-situ X-ray radiographical observation of internal damage development. • Methodology crucial for modelling of dynamic penetration into cellular solids. Processes of internal damage development during localized dynamic penetration represent a crucial mechanism important for relevant analysis of deformation and failure of plates and sandwich panels under high strain rate conditions. Soft cellular materials are of special importance as the internal damage defines mode of collapse and energy absorption capabilities. In this paper, a fast X-ray radiography is employed for in-situ analysis of the internal damage development in soft closed-cell aluminum foam subjected to a localized high strain rate penetration using an instrumented projectile in a direct impact Hopkinson bar apparatus. The process with a typical duration of a few milliseconds is visualized using four X-ray projections acquired using a flash X-ray system and a high-speed camera. Internal damage such as cracking, shear failure in the vicinity of the projectile, and compaction of the material is successfully identified. This unique method utilizing a laboratory based X-ray source allows for characterization of the penetration mechanism that has been usually analyzed only in post-mortem state. [ABSTRACT FROM AUTHOR]

Hot tears can arise during the late part of alloy solidification because of the shrinkage of isolated liquid as it turns to solid and may have a catastrophic effect on cast tensile properties. Although there are correlations to suggest alloy hot tear sensitivity to casting conditions, they do not capture the influence of microstructure on tearing, such as second-phase particles or intermetallic compounds (IMCs) commonly present in engineering alloys. We use in situ X-ray radiography to quantify the formation and growth behaviour of hot tears in Al-5Cu and Al-5Cu-1Fe alloys during solidification. An automated hot tear detection, tracking and merging algorithm is developed and applied to reveal the role of Fe-rich IMC particles, typical of recycled alloys, on hot tear behaviour. These defects are termed hot tears here on the basis of their complex, extended inter-connected morphology, distinct from more rounded shrinkage porosity. We also visualise and quantify the velocity of interdendritic flow driven by solidification shrinkage, and estimate the pressure changes due to shrinkage. Hot tearing starts at lower solid fraction when IMCs are present due to reduced interdendritic flow, and hot tear formation is more spatially homogeneous, less clustered and more numerous. We show that the largest, most damaging hot tears form from many merging events, that is enhanced by the presence of IMCs. [Display omitted] [ABSTRACT FROM AUTHOR]

The visualization of the thawing and desaturation process on an initially saturated, frozen gas diffusion layer (GDL) with a serpentine gas flow channel was performed based on synchrotron X-ray computed tomography images. High speed CT scanning during the experiments allowed the dynamic desaturation process to be quantified under the cold-start with air purging condition. The saturation profiles and the desaturation rates were studied over the entire GDL domain, through-plane, and in selected regions of interest for localized behavior. Sigracet 35AA and 35BA GDLs were selected for the experiments to study the effects of GDL hydrophobicity. Along with the real-time saturation profiles, the average desaturation rates for the entire GDL domain over the whole purging process were 0.000186 μL cm−2 s−1, 0.000470 μL cm−2 s−1, 0.000516 μL cm−2 s−1 and 0.000901 μL cm−2 s−1 with the superficial gas velocity of the purging air at 2.88 m/s, 4.26 m/s, 5.98 m/s and 9.02 m/s, respectively. In addition, the dynamic saturation contours and 3-D GDL geometry models were constructed to show the liquid water movement through a GDL. Although the GDL desaturation curves for each experiment share similar trends, the results show that different conditions including air flow rate, GDL geometric location, initial water saturation, and GDL boundary condition could cause heterogeneous desaturation behavior on both overall and localized GDL regions. These data provide valuable information for future modeling studies that involve the thawing process in the GDL, and could be used to optimize the cell design and develop cold-start protocols. • Dynamic GDL thawing and desaturation profile is quantitatively analyzed via synchrotron X-ray CT. • Higher purging rate speeds up the thawing and desaturation process; GDL hydrophobicity has no significant impact on these. • Overall GDL saturation may not describe the blockage level accurately due to heterogeneity. [ABSTRACT FROM AUTHOR]

In this paper we report a novel way of processing CsI powder into poly-crystalline transparent plate by vacuum hot pressing technique. The fabricated CsI plate is investigated for its microstructure and phase purity. Further we have measured the luminescence and scintillation characteristics of this plate. These measurements establish that the polycrystalline plate can have application in radiation detection. Further the efficacy of the transparent CsI plate is shown for industrial X-ray radiography applications. Our results show that this kind of CsI plate can be economically fabricated and can replace the use of CsI single crystals and thin films in specific applications like radiation detection and industrial radiography. [ABSTRACT FROM AUTHOR]

This study sought to compare point-of-care ultrasound (POCUS) and conventional X-rays for detecting fractures in children. This was a prospective, non-randomized, convenience-sample study conducted in five medical centers. It evaluated pediatric patients with trauma. POCUS and X-ray examination results were treated as dichotomous variables with fracture either present or absent. Descriptive statistics were calculated in addition to prevalence, sensitivity, specificity, positive predictive value and negative predictive value, including 95% confidence intervals (CIs). The Cohen κ coefficient was determined as a measurement of the level of agreement. A total of 554 examinations were performed with POCUS and X-ray. On physical examination, swelling, localized hematoma and functional limitation were found in 66.73%, 33.78% and 53.74% of participants, respectively. The most-studied areas were limbs and hands/feet (58.19% and 38.27%), whereas the thorax was less represented (3.54%). Sensitivity of POCUS was 91.67% (95% CI, 76.41-97.82%) for high-skill providers and 71.50 % (95% CI, 64.75-77.43%) for standard-skill providers. Specificity was 88.89% (95% CI, 73.00-96.34%) and 82.91% (95% CI, 77.82-87.06%) for high- and standard-skill providers, respectively. Positive predictive value was 89.19% (95% CI, 73.64-96.48%) and 75.90% (95% CI, 69.16-81.59%) for high- and standard-skill providers, respectively. Negative predictive value was 91.43% (95% CI, 75.81-97.76%) and 79.44% (95% CI, 74.21-83.87%) for high- and standard-skill providers, respectively. The Cohen κ coefficient showed very good agreement (0.81) for high-skill providers, but moderate agreement (0.54) for standard-skill providers. We noted good diagnostic accuracy of POCUS in evaluating fracture, with excellent sensitivity, specificity, and positive and negative predictive value for high-skill providers. [ABSTRACT FROM AUTHOR]

• After 3 months, all the radiographic features worsened. • Between 3 and 6 months, among the different X-ray abnormalities, only the complete fusion progressed. • Sixteen percent of the patients with vertebral osteomyelitis (VO) still present with a severe to major disability at 6 months. • Vertebral destruction was associated with a higher disability at 6 months. • No differences in radiological progression were observed depending on immobilization. This study aimed to describe radiographic and functional evolution over 6 months in a large cohort of VO patients. We prospectively recruited patients with VO from 2016 to 2019 in 11 French centers. X-rays were performed at baseline, 3 months, and 6 months to assess progression using structural and static criteria. Functional impairment was evaluated using the Oswestry Disability Index (ODI) at 3 months and 6 months. Two hundred and twenty-two patients were included. Mean age was 67.8 ± 14 years, mostly men (67.6%). After 3 months, there was a significant increase in vertebral fusion (16.4% vs 52.7%), destruction of vertebral bodies (10.1% vs 22.8%), and of all the static features (frontal angulation (15.2% vs 24.4%), segmental (34.6% vs 56%) and regional (24.5% vs 41%) kyphosis). From 3 to 6 months, among the different X-ray abnormalities, only the complete fusion progressed significantly (16.6% vs 27.2%). Median ODI showed significant improvement from 3 to 6 months (24, IQR [11.5–38] vs 16, IQR [6–34]). At 6 months, 14.1% of the patients had a severe disability, 2% a major disability. The persistence of vertebral destruction at 6 months was associated with a higher ODI (16, IQR [7.5–30.5] vs 27, IQR [11.5–44.5]). No differences in radiological progression were observed with immobilization using a rigid brace. Our study demonstrates structural and static radiographic progression after 3 months. Only the complete fusion progressed over the long-term. Functional impairment was associated with persistence of vertebral destruction. [ABSTRACT FROM AUTHOR]

Cargo inspection is essential for material discrimination and security aims such as threat detection/identification. In this paper, dual-energy X-ray imaging for cargo inspection is studied. Dual-energy imaging challenges such as improving image quality (i.e. noise reduction), automatically removing image defects and errors, and developing algorithms for image detection and identification are investigated. Selecting the right method for image formation, selecting the right source, choosing appropriate X-ray energies, and the appropriate detectors are also discussed. Cargo inspection using dual-energy X-ray shows that not many techniques have been presented for denoising, and there is no comparative comparison between them. Material discrimination using dual-energy X-ray has had significant success in cargo, especially when convolutional neural network (CNN) is integrated with traditional techniques. However, it will have limitations on performance due to the existence of challenges such as the need for large data and the possibility of noise presence in the extracted features. It seems that future studies should cover these issues. • Dual-energy X-ray radiography has been developed for industrial cargo inspection. • Material discrimination only based on the transparency is not so appropriate. • CNN with traditional techniques gives acceptable success in cargo inspection. • Noise reduction techniques for cargo inspection have a higher research priority. [ABSTRACT FROM AUTHOR]

• A novel evaluation routine for in-depth analysis of radiographic data has been developed and validated. • An evaluation routine for the determination of the dynamic share of the total hold-up is presented and the data show the necessity of a complementary tool to classical computer-tomography. • The presented method is less elaborate, both with regard to experimental effort and evaluation time, thus enabling high-throughput measurement series. Imaging techniques have significantly improved the understanding of fluid dynamics in mass transfer columns over the last decades. In order to detect small-scale and highly dynamic flow phenomena such as droplets, a high spatial and temporal resolution is of crucial importance. One approach is ultrafast electron beam X-ray computed tomography, another is to extend the X-ray computed tomography by a radiographic measuring method. The latter allows a very high spatial and temporal resolution. For example, the X-ray computed tomograph used in the present study allows up to 500 projections per second. This enables the precise detection of highly dynamical effects in the entire column without influencing the flow. A new evaluation routine for radiographic measurements is presented and validated. The procedure enables to measure the liquid hold-up over a wide range with considerable low evaluation times, thus enabling a high experimental throughput. Additionally, a novel method to extract and quantify the dynamic share of the total hold-up is introduced. The possibilities arising from this are then explored utilizing Sulzeŕs structured packing MellapakTM as an example. We compare our findings of the hold-up with published data and discuss how the highly dynamic phenomena affect total flow, its local distribution, and substance dependency. Furthermore, the observations serve as indicator to which extend the computer tomographic method is suited to assess the total hold-up within a structured packing. [ABSTRACT FROM AUTHOR]

• Biplanar radiography allows to accurately quantify the scapula pose and morphology. • The mean bias demonstrated by the accuracy study was under 2 mm for the global shape. • This method could be used as a complementary clinical examination. Patient-specific scapular shape in functional posture can be highly relevant to clinical research. Biplanar radiography is a relevant modality for that purpose with already two existing assessment methods. However, they are either time-consuming or lack accuracy. The aim of this study was to propose a new, more user-friendly and accurate method to determine scapular shape. The proposed method relied on simplified manual inputs and an upgraded version of the first 3D estimate based on statistical inferences and Moving-Least Square (MLS) deformation of a template. Then, manual adjustments, with real-time MLS algorithm and contour matching adjustments with an adapted minimal path method, were added to improve the match between the projected 3D model and the radiographic contours. The accuracy and reproducibility of the method were assessed (with 6 and 12 subjects, respectively). The shape accuracy was in average under 2 mm (1.3 mm in the glenoid region). The reproducibility study on the clinical parameters found intra-observer 95% confidence intervals under 3 mm or 3° for all parameters, except for glenoid inclination and Critical Shoulder Angle, ranging between 3° and 6°. This method is a first step towards an accurate reconstruction of the scapula to assess clinical parameters in a functional posture. This can already be used in clinical research on non-pathologic bones to investigate the scapulothoracic joint in functional position. [ABSTRACT FROM AUTHOR]

Background: The Taylor spatial frame offered the ability of simultaneous correction of the multidirectional deformities without the need to change the frame, and it was widely used for limb lengthening, deformity correction, and fracture reduction in recent years. There are still some inherent limitations that can affect the accuracy of correction, especially for the measurement of the mounting and rotational parameters. The purpose of our study was to propose some more precise postoperative measurement of Taylor spatial frame (TSF) parameters by application of elliptic registration and three-dimensional reconstruction.Methods: This retrospectively study included 28 trauma patients who suffered tibial fracture treated by the TSF at our institution from January 2016 to January 2018, including 25 males and 3 females with a mean age of 43 years (range 14-70 years). We conducted standard full-length anteroposterior and lateral X-rays of the injured extremity and the computed tomographic scans of the bilateral extremities after the operation. Elliptic registration and 3D reconstruction were used to calculate the parameters by two types of software Mimics and CorelDRAW. Correction of the deformity was conducted by adjusting the struts of the TSF according to the electronic prescription. The standard anteroposterior and lateral X-rays after correction were taken to evaluate the effectiveness.Results: All patients acquired functional reduction, which was evaluated by digital radiography. The mean coronal plane translation(1.9±2.2 mm), coronal plane angulation(1.2±1.0°), sagittal plane translation(2.7±2.1 mm), and sagittal plane angulation(1.2±1.0°) after correction were all less than those(5.5±4.6 mm, 4.9±3.9°, 4.7±4.0 mm, 2.7±2.3°) before correction.Conclusions: The TSF system can correct the 6-axis deformities simultaneously with the accurate parameters. Elliptic registration and three-dimensional reconstruction are alternative methods to precisely measure the parameters needed by the TSF system, especially for the mounting and rotational parameters of unusually complex cases. [ABSTRACT FROM AUTHOR]

The formation of primary Fe-rich intermetallic compound crystals and the effect of TiB 2 and TiC inoculation during solidification of a hypereutectic Al-Fe alloy has been investigated. Both horizontal, near isothermal conditions and vertical, directional thermal gradient conditions were studied using laboratory and synchrotron X-ray radiography. TiB 2 and TiC inoculation enhanced formation of Fe-rich intermetallics under all experimental conditions. Near isothermal solidification resulted in the highest intermetallic number density and average formation rate, whilst increasing the thermal gradient reduced both. A model for intermetallic crystal formation is proposed to explain the effect of thermal gradient and cooling rate on the intermetallic number density and average formation rate. [ABSTRACT FROM AUTHOR]

The faceted growth of primary Al 13 Fe 4 intermetallic compounds was studied using in-situ X-ray radiography in a solidifying Al-3Fe alloy. Microscopic twins were frequently observed in the growing intermetallics and were confirmed by post-solidification electron backscatter diffraction. A twin plane re-entrant growth mechanism was suggested, where repeated formation of re-entrant corners facilitated crystal growth along a preferential direction, forming elongated plates. In contrast, for intermetallics where this preferential growth was constrained by surrounding crystals, formation of layered twins perpendicular to the preferential direction was promoted and led to lower aspect ratios, known to be less deleterious to tensile properties. [ABSTRACT FROM AUTHOR]

Background Context: Few studies have described reciprocal changes of pathologic compensatory mechanisms in the setting of spinopelvic fixation using full-body radiograph.Purpose: To elucidate how sagittal alignment of unfused spinal segments and lower extremities change reciprocally following complex thoracolumbar realignment surgery including fusion to the sacrum in adult spinal deformity.Study Design: Retrospective cohort.Patient Sample: Thirty-four patients who underwent fusion from lower thoracic to the sacrum/pelvis and 49 patients with fusion from upper thoracic to the sacrum/pelvis.Outcome Measures: The postoperative sagittal alignment change, and the correlation between the instrumented spinopelvic alignment change and reciprocal changes in unfused spinal segments/lower extremities.Materials/methods: This study included 34 patients who underwent fusion from lower thoracic to the sacrum/pelvis (LT-P group) and 49 patients with fusion from upper thoracic to the sacrum/pelvis (UT-P group). The postoperative sagittal alignment changes were evaluated after subdividing the two groups according to T1 pelvic angle (TPA) (aligned group: TPA<20 and malaligned group: TPA>20). The correlation between the instrumented spinopelvic alignment change (ΔTPA and ΔLL), reciprocal changes in unfused spinal segments and lower extremities, and the cranial sagittal vertical axis-hip/ankle change (ΔCrSVA-Hip/Ankle) were also analyzed.Results: At the baseline in both LT-P and UT-P groups, the patients in the malaligned subgroups showed greater C2-7 lordosis (C2-7L), sacrofemoral angle (SFA), and knee flexion angle (KA) than those in the aligned subgroups. At average 7.1 months postoperatively, these compensatory mechanisms were restored in accordance with instrumented TPA/LL change, especially in the UT-P group. The mid-thoracic alignment changed significantly kyphotic in the LT-P group. ΔTPA and ΔLL linearly correlated with ΔC2-7L, ΔKA, and ΔAA in the malaligned patients. The multivariate regression analysis revealed that change in lower extremity parameters (ΔSFA, ΔKA, and ΔAA) independently impacted ΔCrSVA-Hip/Ankle.Conclusion: Adequate thoracolumbar realignment surgery results in restoration of the pathologic compensatory mechanisms in the unfused spinal segments and lower extremities, especially in patients fused from upper thoracic spine. A preoperative clinical evaluation of the lower limb joints, as well as a full-body radiographic evaluation, is paramount to achieve optimal global sagittal balance in thoracolumbar realignment surgery. [ABSTRACT FROM AUTHOR]

• Synchrotron imaging was applied to ancient papyri with ferrous and plumbiferous ink. • XRF was used for initial, quickly available information about Fe/Pb distribution. • Absorption edge radiography revealed element-sensitive distribution. • Lead carboxylate was identified as pigment of invisible ink by means of FT-IR. In the Egyptian Museum and Papyrus Collection, Berlin, a multitude of papyrus manuscripts are stored. Papyri found on Elephantine island are of special interest. No other settlement in Egypt has been so well documented through texts over four millennia. However, 80% of the Elephantine texts are yet to be documented and published. As part of the "Elephantine" project, funded by an ERC starting grant, we attempt to gain access to hidden text. Most of the fragments are very fragile, deformed, with some rolled or folded. Papyri from the Old and Middle Kingdom were typically written with carbon ink. Consequently, these fragments show no absorption sensitivity for hard X-rays. Also, other inks have been used in those times. If small traces of high-Z elements, like Fe or Pb, are found, absorption may be sensitive enough for radiography and tomography to distinguish between writing and base material. We sorted out suitable fragments and papyrus packages by X-ray fluorescence mapping. When promising high-Z elements were detected, absorption tomography was applied using micro-CT laboratory systems or synchrotron X-rays at the BAMline at BESSY II. The sensitivity can be enhanced by element-sensitive absorption edge imaging, where transmission data taken above and below the edge are compared. This technique was applied at the absorption edges of the elements known to be used as ink and pigment material – Iron, Antimony and Lead. These X-ray results were complemented by Fourier-transform infrared spectroscopy (FT-IR) measurements showing that the lead is found in the form of lead carboxylate. In the future, the presented methodology will be applied to folded or rolled papyri, allowing for analysis of the text without manually opening the fragments. [ABSTRACT FROM AUTHOR]

Evaluate the relationship between structural damage assessed by radiography or ultrasonography in the hands of patients with psoriatic arthritis (PsA) with loss of strength together with functional disability. A cross-sectional study was conducted in patients with PsA involving the hands. Erosions and loss of radiographic joint space were measured in the dominant hand using a modified Sharp van der Heijde method and an ultrasound assessment. Hand strength was assessed with a dynamometer and disability was assessed using the Health Assessment Questionnaire (HAQ). The statistical analysis was performed using multiple linear regression models. 76 patients were included with a mean age of 57 ± 9.9 years, with 56.6% women. A statistically significant relationship was found between presence of erosions and reduction in lateral (p = 0.027) and tip (p = 0.030) pinch strength in the hand. This was also the case for loss of joint space and reduction in lateral (p = 0.012) and tip (p = 0.006) pinch strength. There was an association between total ultrasound (US) alterations and reduction in lateral pinch strength (p = 0.03). An association was also observed between erosions, loss of joint space and total US alterations and disability measured by the HAQ (p < 0.001; <0.001; 0.012, respectively). HAQ scores were associated with a decrease in mean lateral (p < 0.001) and tip (p < 0.001) pinch strength. In patients with PsA involving the hands, structural alterations of the dominant hand assessed by conventional x-ray and ultrasound are associated with loss of strength measured objectively with dynamometry and greater disability also studied subjectively using the HAQ. • Higher scores for erosions and joint space narrowing in the radiography are related to the total HAQ score in a very similar way to loss of strength • In PsA patients, erosions and loss of joint space in the structures involved in the hand pinch action are associated with loss of strength, measured by dynamometry and greater disability measured by the Health Assessment Questionnaire. • The close relationship between Health Assessment Questionnaire score and mean strength measured by dynamometry reveals that measuring strength is a good instrument for studying disability, even in patients with intellectual or language difficulties, and either of the two methods can be applied interchangeably. [ABSTRACT FROM AUTHOR]

In the present work, a dual-energy X-ray radiography system was simulated using MCNPX code. Then, material discrimination curves for graphite, aluminum, steel, and lead materials were obtained using four algorithms, including log-log, R-T, r-θ, and α 1 -α 2. The results show that R-T, r-θ, and α 1 -α 2 algorithms have better performance. Also, due to the less overlap of material discrimination curves for low sample thicknesses, the R-T algorithm can be a better choice for obtaining material discrimination curves in dual-energy radiography systems. • A dual-energy X-ray radiography system was simulated using MCNPX code. • Material discrimination curves were obtained using four algorithms. • R-T algorithm is a proper choice for dual-energy radiography systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Deep learning was able to label defects in X-ray radiographs of pear fruit. • A large amount of ground truth data were obtained by simulations from X-ray CT data. • Synthetic training data improved segmentation of browning and cavity defects. A particular challenge for food quality inspection remains the quantification of internal defects. This work addresses the challenge of internal defects segmentation in pear fruit (cv. Conference) based on high-throughput inline X-ray radiography images in combination with deep learning. Unlike previous approaches, which focused on healthy vs defect classification, the current segmentation approach is able to determine the type of defect, its dimensions, and location. To this end, a novel simulation method was designed to obtain input-target image pairs of radiography data, and more diverse defect pears were generated using a conditioned generator model. The obtained data contributed to the design of a segmentation model that labeled every pixel in the X-ray radiographs of pear fruit as 'external air', 'healthy tissue', 'core', 'browning', or 'cavity'. We demonstrated that additional synthetic data in the learning process drastically improved the model performance. For instance, the mean IoU increased from 0.781 ± 0.112 to 0.883 ± 0.088 for consumable pears with minor cavities and browning. In terms of utility, our segmentation maps provide more detailed information about the type, size, and location of the disorders compared to the heatmaps produced by existing benchmark classifiers. [ABSTRACT FROM AUTHOR]

The results of the development of a radiographic installation that allows to control the size of the internal elements of HPGe detectors' cryostats for simulation by Monte Carlo method, are presented. Calibration and assessment of image quality value of the developed radiographic installation were carried out in accordance with ISO Standards 19232–1 and 19232–5. Simulation of the HPGe detector's registration efficiency in the range of 50 keV-3 MeV with the MCC-MT program showed that the discrepancy between the calculated and experimental results when adjusting the detector model using radiological measurement data does not exceed 3% in geometry for point sources and 5% for the Eu-152 source in the Marinelli beaker geometry. • A simple, reliable and economical X-ray radiographic installation is designed for measuring necessary sizes of HPGe detectors in cryostats. • Standard uncertainty in determining linear dimensions of the elements behind the wall of the cryostat aluminum cap is ±0.1 mm. • The developed radiological installation has passed the calibration and image quality value assessment. in accordance with ISO Standards 19,232–1 and 19,232–5. • To assess the effect of the accuracy of HPGe detectors' real size on the results of the experiments, Monte Carlo simulations of registration efficiency in HPGe detector's range of 50 keV - 3 MeV were carried out. • The dcrepancy between the calculated and experimental results when adjusting the detector model by using radiological measurement data are presented. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dual-energy X-ray radiography is utilized for material discrimination. • Modular radial basis networks are applied for training of X-ray images. • The approach is based on identification of quasi-radial distributions of spectrums. • The results show acceptable discrimination of material-thicknesses. Challenges, especially, identification of correlation of attenuation coefficients at high/low energy X-ray, stochastic noise on images, source energy fluctuation, and angular drop-off of X-ray energy/dose rate affect the quality of the material discrimination using dual-energy X-ray radiography. In this study, a new approach using radial basis network (RBN) is applied for the identification of materials. A modular structure, in which each module is responsible for the identification of a single material-thickness is developed. Each module with its specific RBN not only is trained to identify its own material-thickness but also is trained to reject the other ones. The activation/radial function of each network is with standard deviation proportional to the distribution of a specific material-thickness transparency. This technique tries to handle the effects of the mentioned challenges which have quasi-radial distribution on the constructed image. Moreover, the cross-correlation between attenuation coefficients at high/low energy X-ray is detected by the neural network. The results show an acceptable performance of the proposed approach. The noticeable advantages are: 1- Instead of utilizing qualitative discrimination techniques such as pseudo-colouring, the materials are discriminated quantitatively which is more important when the number of material- thicknesses is increased. 2- The modular structure makes it possible to add new material- thickness without unfavourably affecting the existing networks (i.e., there is no need to retrain them). 3- The exact percentage of correct identification, incorrect identification, and misidentification are given 4- Bipolar representation makes possible to identify material-thickness without need/with less need to human operators 5- Material discrimination may be done by a more straightforward computational tool because classical machine learning is applied instead of deep learning. [ABSTRACT FROM AUTHOR]

Mn doping in water-soluble C 4 H 12 N 2 Zn X 4 crystal produces a boosting PLQY from < 1 % to ∼99 % under the blue light excitation, which is applied in solid-state lighting and X-ray radiography. [Display omitted] • Record X-ray radiography capability (6–9 LP/mm) in hybrid Zn-based halides. • An eco-friendly WLED materials with LE of 98.52 lm/W and CRI of 83.3. • Boosting PLQY from Mn dopant explained by theoretical study. Zero-dimensional (0D) metal halides based on environmental friendliness, low cost, and earth-abundant elements have gained tremendous attention because of their applications including solid-state lighting, X-ray radiography, anti-counterfeiting labels and beyond. Herein, Mn-doped 0D C 4 H 12 N 2 Zn X 4 (X = Cl and Br) with strong green emission has been developed in the application of the scintillator and the white light-emitting diode (WLED). Spectroscopic studies and density functional theory (DFT) calculations clarify the Mn doping effect on the electronic structure of C 4 H 12 N 2 Zn X 4. The Mn doping reduces the bandgap owing to the Mn 3d contribution to VBM. The hybrid of Mn 3d orbitals with Br 4p/ Cl 3p enhances the Mn(II) d-d emission resulting in a maximum photoluminescence quantum yield (PLQY) of 99 % in Mn-doped C 4 H 12 N 2 Zn X 4. Therefore, the WLED using Mn-doped C 4 H 12 N 2 Zn X 4 as a green phosphor shows a high luminous efficacy of 98.52 lm/W and a CRI of 83.3, which is better than other similar WLEDs based on CsPb X 3 or Mn-doped Cs 2 Zn X 4. Impressively, Mn-doped C 4 H 12 N 2 Zn X 4 ceramic wafer has X-ray radiography with 6–9 LP/mm spatial resolution better than CsI: Tl or MAPbI 3. [ABSTRACT FROM AUTHOR]

• High-speed synchrotron X-rays reveal rich liquid core states of coaxial atomization. • Transition from a liquid column to an upside-down crown as gas flow increases. • Air pockets, dewetting and ligaments found where a continuous phase is expected. • Swirling gas produces liquid core drastic dewetting and back-and-forth motions. • Bi-stability introduces new timescales and massive changes in boundary layers. The liquid core of a canonical two-fluid coaxial atomizer has been characterized using synchrotron X-rays. The high energy photons allow for high-speed imaging of attenuation through the dense liquid-gas jet core, resolving the internal structures that include entrapped air bubbles and the formation of liquid ligaments and bags. When the gas-to-liquid momentum ratio increases, the liquid core transitions from an intact column, where primary break-up happens several liquid diameters downstream, to a hollow crown with a downstream span comparable to the liquid diameter that disintegrates by shedding ligaments from its rim. At high gas momentum ratios (limited by the sonic velocity at the gas nozzle exit), this crown suffers partial dewetting and, when angular momentum is added to the gas, it dewets on a large section of the liquid injection needle circumference. This partial crown exhibits azimuthal motions along the circumference, on timescales much longer than the relevant flow timescales. The crown attachment to the liquid needle presents a bi-stable nature. The dramatic changes of the liquid core morphology, as the gas momentum and swirl ratios vary, have a strong impact on the gas-liquid boundary layers, which control the liquid break-up mechanisms and the resulting spray characteristics, such as droplet size distributions and the droplet volume fraction across the spray. [ABSTRACT FROM AUTHOR]

Purpose: The present investigation was done to assess the status of tear film and corneal topography in individuals with long-term exposure to X-ray.Method: This historical cohort study was carried out to compare the lacrimal and corneal findings between radiographers (n = 126) and non-radiographers (n = 172). Radiographers included individuals with at least 5 years of experience in radiography while subjects in the control group had no history of exposure to X-ray. The Ocular Surface Disease Index (OSDI) was filled out by all individuals. Besides, the Pentacam imaging of both eyes was done. Finally, the lacrimal tests including tear break-up time and Schirmer (with anesthesia) were performed for both eyes of the participants.Results: The mean values of the Schirmer and Tear breakup time (TBUT) in the radiographer group (Schirmer: 11.1 ± 3.2 mm, TBUT: 11.3 ± 4.1 s) were significantly lower than the values in control group (14.6 ± 8.1 mm, TBUT: 12.8 ± 4.8 s) (P < 0.0001). The mean OSDI score of the radiographers was significantly higher compared to the control group (24.1 ± 17.6, and 12.3 ± 12.4 respectively (P < 0.0001)). The corneal thickness in the center, inferior, superior, temporal and nasal parts was significantly higher in radiographers versus the control group. In addition, the maximum thickness difference was observed in temporal part (34.00 μm thicker) (P < 0.0001). On the other hand, the corneal eccentricity factor was lower in radiographers compared to the control group (P < 0.0001).Conclusion: Based on the findings of this study, it is concluded that the radiographers have thicker and flatter corneas are than the corneas of the subjects in the control group. However, their corneas had no irregularities. Regarding the tear point, a higher prevalence of dry eye symptoms was observed in the radiographers compared to the control group. [ABSTRACT FROM AUTHOR]

Abstract X-ray radiography is widely used as a non-destructive method for defect detection and quality checks of nuclear fuel rod's components in the fabrication process. In this paper, an approach based on Monte Carlo method is proposed to obtain optimum filter and exposure parameters such tube voltage, current and exposure for digital radiography of a nuclear fuel rod including UO 2 pellets with a maximum diameter of 11.9 mm. Monte Carlo N-Particle (MCNP) code was implemented to model an digital X-ray radiography system composed of an industrial X-ray machine and a computed radiography phosphor imaging plate. Three main image quality parameters of contrast, resolution and signal to noise ratio (SNR) were evaluated in various exposure conditions. The results show that using a Cu intermediate filter with a thickness of 0.5 mm and a tube voltage in the range of 400–500kV with a minimum exposure of 20 mA min, can provide the highest quality for imaging the mentioned fuel rod. Moreover, the highest quality can be also achieved for tube voltages in the range of 500–600kV in condition that a minimum exposure of 40 mA min is provided. In addition to obtaining optimum conditions, the mentioned method can propose best exposure conditions proportional to the limitation of laboratory apparatuses. As a case study, the obtained results from simulation were implemented for the existence apparatuses in our laboratory and then an experimental work was carried out. The laboratory apparatuses included an X-ray machine with a peak voltage of 300 kV and a standard phosphor imaging plate. In the obtained experimental image, the details and components of the fuel rods including pellets, springs, Zircaloy clad and also the gap between the pellets were clearly observed. The proposed method can easily be implemented for all types of nuclear fuels with various dimensions and material types. Highlights • A Monte Carlo method proposed to optimize exposure parameters for fuel rod imaging. • Contrast, resolution and SNR were evaluated in various exposures using MCNP code. • Selection of tube voltage, exposure and filter to provide highest image quality was studied. • Experimental imaging of 3 fuel rods were done based on simulation results. [ABSTRACT FROM AUTHOR]

Highlights • We propose two novel neural network architectures to detect pulmonary lesions in chest x-rays imagesthat use visual attention mechanisms. • The architectures are designed to learn from a large number of weakly-labelled images (class labels only) and a small number of annotated images (bounding boxes). • The algorithms and trained and tested using a large dataset of over 700k chest x-ray exams extracted from two hospital's archives and processed using a novel NLP pipeline. • Results are validated on 6,131 manually labelled exams from two independent radiologists. • Our experimental resultsare either in line or better than currently reported performance from other studies. Graphical abstract Abstract Machine learning approaches hold great potential for the automated detection of lung nodules on chest radiographs, but training algorithms requires very large amounts of manually annotated radiographs, which are difficult to obtain. The increasing availability of PACS (Picture Archiving and Communication System), is laying the technological foundations needed to make available large volumes of clinical data and images from hospital archives. Binary labels indicating whether a radiograph contains a pulmonary lesion can be extracted at scale, using natural language processing algorithms. In this study, we propose two novel neural networks for the detection of chest radiographs containing pulmonary lesions. Both architectures make use of a large number of weakly-labelled images combined with a smaller number of manually annotated x-rays. The annotated lesions are used during training to deliver a type of visual attention feedback informing the networks about their lesion localisation performance. The first architecture extracts saliency maps from high-level convolutional layers and compares the inferred position of a lesion against the true position when this information is available; a localisation error is then back-propagated along with the softmax classification error. The second approach consists of a recurrent attention model that learns to observe a short sequence of smaller image portions through reinforcement learning; the reward function penalises the exploration of areas, within an image, that are unlikely to contain nodules. Using a repository of over 430,000 historical chest radiographs, we present and discuss the proposed methods over related architectures that use either weakly-labelled or annotated images only. [ABSTRACT FROM AUTHOR]

Background: Surface topography is a radiation-free examination that provides relevant information for the evaluation of patients with Adolescent Idiopathic Scoliosis (AIS). However, its usage is not standardized, which restricts the applicability of this instrument.Research Questions: (a) To identify the anatomical reference markers used on surface topography; (b) to identify the parameters used on surface topography; and (c) to pool correlation and reproducibility results.Methods: Systematic searches were conducted following MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines. The methodological quality was assessed according to Brink & Louw appraisal tool.Results: Twenty-three studies were included for the qualitative synthesis. The most commonly used anatomical reference markers were: the prominent vertebra (C7 or T1), the posterior superior iliac spines (PSISs) and the sacrum (S1). The parameters for the evaluation of the AIS by surface topography are: spinal inclination angle (analogous to Cobb), gibbosity, thoracic kyphosis angle, lumbar lordosis angle, pelvic obliquity, spine length, apex of the curve, C7-S1 distance (frontal plane), and C7-S1 displacement (sagittal plane). Data from eleven studies were metanalyzed and evidenced the correlation of the surface topography with X-ray exams and the reproducibility of the surface topography in the sagittal and frontal planes.Significance: The findings of this study recommend the use of a protocol for the application of the equipment. The analyzed studies predict the use of only four markers for anatomical reference. The evaluation of the AIS can be carried out observing nine parameters. Surface topography correlates with radiography when the spinal inclination angle (Cobb angle), thoracic kyphosis angle and lumbar lordosis angle are compared. Also, surface topography presents inter and intra-rater reproducibility in the sagittal plane and intra-rater reproducibility in the frontal plane. [ABSTRACT FROM AUTHOR]

Abstract Radiographic inspection of welds in non-standard industrial components often require development of new techniques or modifications to existing ones on the basis of geometry, size, sensitivity requirements, accessibility, nature of defects expected etc. This paper proposes a modified Double Wall Technique (DWT) for evaluation of a weldment in cylindrical component fabricated by Gas Tungsten Arc Welding (GTAW) for use in nuclear facility. The technique has been validated by experimental measurements using film-based gamma radiography with Iridium-192 source. The study also includes evaluation of other joints of the component by X-ray computed radiography (CR) modality. The experimental results show that the proposed technique has met ASME Section V code requirements and yields contrast sensitivity of about 2%. Highlights • Radiographic investigation on weld integrity in a non-standard industrial component for nuclear application. • Study using Double Wall Techniques (DWT) by conventional radiography with Ir-192 source and X-ray Computed Radiography (CR). • Proposed a modified DWT technique to evaluate a weldment of the non-standard component. • Experimentally achieved image quality complies with the relevant ASME code and yields contrast sensitivity of about 2%. • The study is also expected to augment better and expanded utilization of CR modality in an industrial environment. [ABSTRACT FROM AUTHOR]

Objectives: Current guidelines recommend chest computed tomography (CT) with locoregional CT/magnetic resonance imaging for patients with head and neck squamous cell carcinoma (HNSCC), and 18F-fluorodeoxyglucose (FDG) positron-emission tomography (PET)/CT is suggested for stage III-IV patients. However, whole body screening with 18F-FDG PET/CT may provide better detection of distant metastases and synchronous cancer than conventional imaging. We evaluated the utility of 18F-FDG PET/CT in detecting distant metastasis and synchronous cancer.Methods: This prospective study enrolled 740 consecutive patients with previously untreated HNSCC diagnosed between September 2010 and December 2015. Synchronous cancer was histologically confirmed and distant metastases were confirmed by biopsy or serial imaging follow-ups. McNemar test was used to compare the true-positive detection rates of chest radiography (CXR) + head and neck CT (hnCT) (A) versus 18F-FDG PET/CT (C) and chest CT + hnCT (B) versus 18F-FDG PET/CT.Results: Distant metastases and synchronous cancer were found in 23 (3.1%) and 55 (7.4%) patients, respectively. A, B, and C detected distant metastases in 10 (1.3%), 19 (2.6%), and 21 (2.8%) patients, respectively. The absolute differences were 1.5% (A versus C, P = 0.003) and 0.3% (B versus C, P = 0.687). A, B, and C detected synchronous cancer in 15 (2.0%), 22 (2.9%), and 36 (4.9%) patients, respectively. The absolute differences were 2.8% (A versus C, P < 0.001) and 1.4% (B versus C, P = 0.013).Conclusions: 18F-FDG PET/CT detected more distant metastases and synchronous cancer than CXR + hnCT and more synchronous cancer than chest CT + hnCT. [ABSTRACT FROM AUTHOR]

Background: Akin osteotomy is a well-known surgical procedure in forefoot surgery. When performing percutaneously, we have found a lot of delayed unions on follow up X-rays. The objective of this study was to assess the incidence of delayed union when performing a percutaneous Akin osteotomy.Methods: We report a series of 26 cases who underwent minimally invasive (percutaneous) Akin osteotomy. The mean follow-up duration was 17.6 (range 12 to 24) months. We analys-24) months. We analyzed the time to fusion using standard weight bearing radiographs. All the procedures were uneventful and we had only two skin burns that healed without sequelae.Results: All the procedures were uneventful and we had only two skin burns that healed without sequelae. The average time to fusion in our series was 4.69 months (2-11): seventeen of the 26 osteotomies (65.4%) were considered radiographically healed at an average time of 2,94 months (2-5), whereas 9 patients (34.6%) sustained a delayed-union and healed at an average of 8 months (7-11).Conclusions: Despite few intraoperative complications and satisfactory clinical and radiological outcomes, our data suggest that a delayed union after Akin osteotomy is very common in the daily practice when performing it through a minimally invasive technique. [ABSTRACT FROM AUTHOR]

Introduction: The genetic Lauge-Hansen classification has been traditionally used for reconstruction of the mechanism of ankle injury. The ability of the Lauge-Hansen classification to predict actual mechanism of the injury has been questioned in recent studies, leaving a void in medicolegal reasoning. The aim of this study is to identify morphologic features of malleolar fractures on plain X-rays that may be used to reveal the fracture mechanism.Material and Methods: Radiographs of 78 patients with acute malleolar fractures were analyzed and compared with fracture mechanisms reported by these patients.Results: A modified Pankovich classification of medial malleolus fractures and the presence of a posterior malleolus fracture were able to significantly predict the mechanism of fracture reported by the patient (p<0.05). Lateral fracture morphology was not useful for predicting the fracture mechanism except for infrasyndesmotic fractures pointing to a supination mechanism.Conclusion: A supination mechanism of the fracture can be predicted by observing pure ligamentous or chip-avulsion deltoid injury. The presence of an anterior colliculus fracture of the medial malleolus is correlated with a pronation mechanism. A fracture of the posterior malleolus correlates with pronation while an intact posterior malleolus correlateds with supination as a fracture mechanism. Absolute determination of fracture mechanism from the X-ray morphology of the fracture is impossible in the majority of cases. [ABSTRACT FROM AUTHOR]

Thermal neutron radiography and X-ray radiography are characterised by different penetration depths in various materials, for example in collagen and hydroxyapatite, two major components of bone. Neutron radiography penetrates hydroxyapatite easier than collagen and, conversely, in X-ray radiography attenuation is higher in hydroxyapatite than in collagen. This effect allows estimation of collagen presence in dry bone. In our study we show that differences between the two imaging methods are sufficient to produce significant results when bone areas with higher and lower content of collagen are being compared. [ABSTRACT FROM AUTHOR]

Purpose To use a CT-based approach with 3D modeling to determine novel radiographic views of the scaphotrapezial (STl) and scaphotrapezoid (STd) joints. Materials and methods Consecutive wrist CT scans excluding those with pathology of the distal radius, scaphoid, trapezium, or trapezoid of subjects between ages 18 and 60 years were retrospectively reviewed. Three-dimensional reconstructions of CT scans were created and best-fit planes of the STl and STd joints were generated. Angles of these planes relative to a distal radial coordinate system were calculated to determine tilt of the wrist and the X-ray beam for novel radiographic views of these joints. Results Fifty eligible wrist CT scans were identified. The mean age was 38 years (range, 18 to 59). For the novel STl PA view, the wrist is supinated 17° from the standard PA view and the X-ray beam is canted 6° caudad. In the STl lateral view, the wrist is pronated 17° from the standard lateral view, and the X-ray beam is canted 20° caudad. In the STd PA tilt view, the wrist is supinated 28° from the standard PA view, and the X-ray beam is canted 13° caudad. In the STd joint lateral tilt view, the wrist is pronated 28° from the standard lateral view, and the X-ray beam is canted 29° caudad. Conclusion We describe novel radiographic views of the STl and STd joints based on 3D modeling of wrist CT scans. Further studies are required to assess the efficacy of these views in detecting joint pathology. [ABSTRACT FROM AUTHOR]

• X-ray radiographs give projected mass information that may be degraded due to blur. • Proposed framework allows for correcting mass information in degraded radiographs. • Penalized regression model trained with artificially-blurred synthetic objects. • Experimental feasibility showcased on real radiographs of solid objects. • Blind construction allows for correcting mass without knowing the system PSF. The quantitative impact of image blur on calculated object mass in X-ray radiography is explored. Radiographed object masses are initially estimated through experimental calibration and compared against their known true mass, with the deviation, or "apparent mass loss". Apparent mass loss occurs due to the effect of spatial blur on X-ray transmission images that reduces the measured mass because while the image intensity is conserved with spatial blur, the nonlinear conversion to path length is not. A synthetic model is proposed where an object's apparent mass loss is estimated through the amount of blur present within the radiograph image. The image blur is inferred through a combination of readily available image parameters related to the signal levels, object shape, and experimental extrinsics. A regularized regression model is built that correlates these blur parameters to the expected mass loss. The model is first trained on 2100 and tested on 140 synthetically created objects, and then later verified on two separate experimental setups of type 304 stainless steel objects imaged with a portable tube source at 150 kVp and type 6061 aluminum objects at 80 kVp. The proposed model allows for a simple post hoc reduction in errors of approximately 20% in object mass through X-ray radiography. [ABSTRACT FROM AUTHOR]

The suspension of a heavy sphere by an upward jet is a classical fluid mechanics experiment to demonstrate the fluid forces acting on an object. In the range of the parameter space where the sphere can be suspended, the dynamics can either be regular, i.e., with oscillations around an equilibrium position, or chaotic, with extreme events leading to large deviations from that equilibrium region. The existence and characteristics of suspension regimes of several heavy spheres in such flow configurations remain open questions. Spheres compete for the equilibrium position and come very close to each other, resulting in large local particle concentrations that prevent direct imaging. Relatively high speed X-ray radiography along with the radioSphereanalysis technique is leveraged here to study the time-resolved 3D trajectory of each individual sphere in a vertical jet. radioSphereis an X-ray analysis method that retrieves the 3D information out of a single 2D radiography using a priori knowledge of the imaging geometry (E. Andò et al., 2021), which due to the imaging modality imposes no limitations on the optical properties of the water. The 3D ＋ time kinematics yield the evolution of the statistics of the position and velocity of the spheres as a function of the number of spheres and for two jet Reynolds numbers. Drastic changes in behavior occur when many spheres are present, leaving a clear signature on the temporal dynamics and on the exploration of the flow volume, where spheres can remain on the bottom of the vessel for long periods of time, resulting in only partial suspension. In addition to the suspension capacity, the interactions between spheres are explored with statistics of pair separation distances, which, together, allow for quantitative arguments to introduce suspension regimes of a collection of spheres in an upward vertical jet. • The suspension dynamics of heavy spheres in an upward vertical jet are studied. • Time-resolved radiography combined with the radioSphere method yields 4D kinematics. • Statistics of the spheres' position and velocity and temporal dynamics are explored. • The interactions between spheres drastically change the dynamics and flow sampling. • Collective suspension regimes are introduced quantitatively based on interactions. [ABSTRACT FROM AUTHOR]

A method was developed based on synchrotron X-ray radiography to estimate tip temperatures of 203 Fe-rich intermetallic compound (IMC) particles during directional solidification of Al-Cu-Fe alloys. Tip temperatures showed two distinct IMC populations corresponding to Al 6 (Fe,Cu) and Al 7 Cu 2 Fe, validated by post-solidification microscopy. The IMC tip undercooling of each growing IMC was estimated by comparison with its equilibrium formation temperature. The effect of Fe concentration, cooling rate and grain refiner additions on the IMC tip undercooling was studied. With a large number of IMC particles measured, we show the relationship between solidification parameters, secondary IMC selection and tip undercooling. [ABSTRACT FROM AUTHOR]

Megavoltage (MV) radiography has important applications in imaging large cargos for detecting illicit materials. A useful feature of MV radiography is the possibility of decomposing and quantifying materials with different atomic numbers. This can be achieved by imaging cargo at two different X-ray energies, or dual energy (DE) radiography. The performance of both single energy and DE radiography depends on beam energy, beam filtration, radiation dose, object size, and object content. The purpose of this work was to perform comprehensive qualitative and quantitative investigations of the image quality in MV radiography depending on the above parameters. A digital phantom was designed including Fe background with thicknesses of 2cm, 6cm, and 18cm, and materials samples of Polyethylene, Fe, Pb, and U. The single energy images were generated at x-ray beam energies 3.5MV, 6MV, and 9MV. The DE material decomposed images were generated using interlaced low and high energy beams 3.5/6MV and 6/9MV. The X-ray beams were filtered by low-Z (Polyethylene) and high-Z (Pb) filters with variable thicknesses. The radiation output of the accelerator was kept constant for all beam energies. The image quality metrics was signal-to-noise ratio (SNR) of the particular sample over a particular background. It was found that the SNR depends on the above parameters in a complex way, but can be optimized by selecting a particular set of parameters. For some imaging setups increased filter thicknesses, while strongly absorbing the beams, increased the SNR of material decomposed images. Beam hardening due to polyenergetic x-ray spectra resulted in material decomposition errors, but this could be addressed using region of interest decomposition. It was shown that it is not feasible to separate the materials with close atomic numbers using the DE method. Particularly, Pb and U were difficult to decompose, at least at the dose levels allowed by radiation source and safety requirements. [ABSTRACT FROM AUTHOR]

Objective: Pelvic x-ray is frequently used as a screening tool during initial assessment of injured patients. However routine use in the awake and alert blunt trauma patient may be questioned due to low yield. We propose a clinical tool that may avoid unnecessary imaging by examining whether the ability to straight leg raise, without pain, can rule out pelvic injury.Methods: We conducted a prospective cohort study with the exposure variables of ability to straight leg raise and presence of pain on doing so, and presence of pelvic fracture on x-ray as the primary outcome variable.Results: Of the 328 participants, 35 had pelvic fractures, and of these 32 were either unable to straight leg raise, or had pain on doing so, with a sensitivity of 91.43% (95% CI: 76.94-98.2%) and a negative predictive value of 98.57% (95% CI: 95.88-99.70%). The 3 participants with a pelvic fracture who could straight leg raise with no pain, all had a GCS of less than 15, and therefore, among the sub-group of patients with GCS15, a 100% sensitivity and 100% negative predictive value for straight leg raise with no pain to rule out pelvic fracture was demonstrated.Conclusion: Among awake, alert patients, painless straight leg raise can exclude pelvic fractures and be incorporated into initial examination during reception and resuscitation of injured patients. [ABSTRACT FROM AUTHOR]

Abstract Using synchrotron X-ray high speed radiography, the fragmentation and refinement of pre-existing primary Al 2 Cu intermetallic dendrites induced by ultrasonic melt processing in a hypereutectic Al-35% Cu alloy were studied in-situ and in real time. The alloy was melted, contained and processed in a quartz tube crucible with a middle section of approximately 300 μm-thick channel where the observations were made. Direct observation of intermetallic fragmentation and detachment unambiguously confirms that the acoustic cavitation and streaming flow play a crucial role in fragmentation of the intermetallic dendrites. Furthermore, the remelting effect due to transport of hot liquid via acoustic streaming flow and the stress against the intermetallic dendrites caused by acoustic streaming flow are found to be the dominant fragmentation mechanism in the present experiments. It is also suggested that cavitation bubbles or bubble clouds contribute to fragmentation not only by mechanically fracturing the dendrites but also by facilitating the effect of acoustic streaming flow on dendrites. At last, clear observation of equiaxed intermetallic dendrites growing from small fragments after ultrasonic melt processing provides the first conclusive evidence of the refinement mechanism, i.e. the acoustic cavitation and acoustic streaming flow progressively break the intermetallic dendrites into small fragments. Most of these small fragments are able to survive and then act as nuclei for the subsequent solidification of intermetallic phases, consequently leading to intermetallic refinement in the solidified microstructure. [ABSTRACT FROM AUTHOR]

Background Diastatic skull fractures (DSFs) in children are difficult to detect in skull radiographs before they develop into growing skull fractures; therefore, little information is available on this topic. However, recent advances in 3-dimensional (3D) computed tomography (CT) imaging technology have enabled more accurate diagnoses of almost all forms of skull fracture. The present study was undertaken to document the clinical characteristics of DSFs in children and to determine whether 3D CT enhances diagnostic accuracy. Methods Two hundred and ninety-two children younger than 12 years with skull fractures underwent simple skull radiography, 2-dimensional (2D) CT, and 3DCT. Results were compared with respect to fracture type, location, associated lesions, and accuracy of diagnosis. Results DSFs were diagnosed in 44 (15.7%) of children with skull fractures. Twenty-two patients had DSFs only, and the other 22 had DSFs combined with compound or mixed skull fractures. The most common fracture locations were the occipitomastoid (25%) and lambdoid (15.9%). Accompanying lesions consisted of subgaleal hemorrhages (42/44), epidural hemorrhages (32/44), pneumocephalus (17/44), and subdural hemorrhages (3/44). A total of 17 surgical procedures were performed on 15 of the 44 patients. Fourteen and 19 patients were confirmed to have DSFs by skull radiography and 2D CT, respectively, but 3D CT detected DSFs in 43 of the 44 children ( P < 0.001). Conclusion 3D CT was found to be markedly superior to skull radiography or 2D CT for detecting DSFs. This finding indicates that 3D CT should be used routinely rather than 2D CT for the assessment of pediatric head trauma. [ABSTRACT FROM AUTHOR]

This paper focuses on the use of X-rays in their largest field of application: medical diagnostic imaging and image-guided therapy. For this purpose, vacuum electronics in the form of X-ray tubes as the source of bremsstrahlung (braking radiation) have been the number one choice for X-ray production in the range of photon energies between about 16 keV for mammography and 150 keV for general radiography. Soft tissue on one end and bony structures on the other are sufficiently transparent and the contrast delivered by difference of absorption is sufficiently high for this spectral range. The dominance of X-ray tubes holds even more than 120 years after Conrad Roentgen’s discovery of the bremsstrahlung mechanism. What are the specifics of current X-ray tubes and their medical diagnostic applications? How may the next available technology at or beyond the horizon look like? Can we hope for substantial game changers? Will flat panel sources, less expensive X-ray “LED’s”, compact X-ray Lasers, compact synchrotrons or equivalent X-ray sources appear in medical diagnostic imaging soon? After discussing the various modalities of imaging systems and their sources of radiation, this overview will briefly touch on the physics of bremsstrahlung generation, key characteristics of X-ray tubes, and material boundary conditions, which restrict performance. It will discuss the deficits of the bremsstrahlung technology and try to sketch future alternatives and their prospects of implementation in medical diagnostics. [ABSTRACT FROM AUTHOR]

In this work, an outward-opening compressed natural gas, direct injection fuel injector has been studied with single-shot X-ray radiography. Three dimensional simulations have also been performed to compliment the X-ray data. Argon was used as a surrogate gas for experimental and safety reasons. This technique allows the acquisition of a quantitative mapping of the ensemble-average and standard deviation of the projected density throughout the injection event. Two dimensional, ensemble average and standard deviation data are presented to investigate the quasi-steady-state behavior of the jet. Upstream of the stagnation zone, minimal shot-to-shot variation is observed. Downstream of the stagnation zone, bulk mixing is observed as the jet transitions to a subsonic turbulent jet. From the time averaged data, individual slices at all downstream locations are extracted and an Abel inversion was performed to compute the radial density distribution, which was interpolated to create three dimensional visualizations. The Abel reconstructions reveal that upstream of the stagnation zone, the gas forms an annulus with high argon density and large density gradients. Inside this annulus, a recirculation region with low argon density exists. Downstream, the jet transitions to a fully turbulent jet with Gaussian argon density distributions. This experimental data is intended to serve as a quantitative benchmark for simulations. [ABSTRACT FROM AUTHOR]

Aim: To investigate image interpretation performance by diagnostic radiography students, diagnostic radiographers and reporting radiographers by computing eye gaze metrics using eye tracking technology.Methods: Three groups of participants were studied during their interpretation of 8 digital radiographic images including the axial and appendicular skeleton, and chest (prevalence of normal images was 12.5%). A total of 464 image interpretations were collected. Participants consisted of 21 radiography students, 19 qualified radiographers and 18 qualified reporting radiographers who were further qualified to report on the musculoskeletal (MSK) system.Outcome Measures: Eye tracking data was collected using the Tobii X60 eye tracker and subsequently eye gaze metrics were computed. Voice recordings, confidence levels and diagnoses provided a clear demonstration of the image interpretation and the cognitive processes undertaken by each participant. A questionnaire afforded the participants an opportunity to offer information on their experience in image interpretation and their opinion on the eye tracking technology.Results: Reporting radiographers demonstrated a 15% greater accuracy rate (p≤0.001), were more confident (p≤0.001) and took a mean of 2.4s longer to clinically decide on all features compared to students. Reporting radiographers also had a 15% greater accuracy rate (p≤0.001), were more confident (p≤0.001) and took longer to clinically decide on an image diagnosis (p=0.02) than radiographers. Reporting radiographers had a greater mean fixation duration (p=0.01), mean fixation count (p=0.04) and mean visit count (p=0.04) within the areas of pathology compared to students. Eye tracking patterns, presented within heat maps, were a good reflection of group expertise and search strategies. Eye gaze metrics such as time to first fixate, fixation count, fixation duration and visit count within the areas of pathology were indicative of the radiographer's competency.Conclusion: The accuracy and confidence of each group could be reflected in the variability of their eye tracking heat maps. Participants' thoughts and decisions were quantified using the eye tracking data. Eye tracking metrics also reflected the different search strategies that each group of participants adopted during their image interpretations. This is the first study to use eye tracking technology to assess image interpretation skills between various groups of different levels of experience in radiography, especially on a combination of the MSK system, chest cavity and a variety of pathologies. [ABSTRACT FROM AUTHOR]

Imaging technology is generally considered too invasive for arms control inspections due to the concern that it cannot properly secure sensitive features of the inspected item. However, this same sensitive information, which could include direct information on the form and function of the items under inspection, could be used for robust arms control inspections. The single-pixel X-ray imager (SPXI) is introduced as a method to make such inspections, capturing the salient spatial information of an object in a secure manner while never forming an actual image. The method is built on the theory of compressive sensing and the single pixel optical camera. The performance of the system is quantified using simulated inspections of simple objects. Measures of the robustness and security of the method are introduced and used to determine how robust and secure such an inspection would be. In particular, it is found that an inspection with low noise (~ < 1 % ) and high undersampling (~ > 256 × ) exhibits high robustness and security. [ABSTRACT FROM AUTHOR]