Synchrotron Radiation Computed Tomography Research Articles

In situ synchrotron computed tomography study of nanoscale interlaminar reinforcement and thin-ply effects on damage progression in composite laminates

In situ X-ray synchrotron radiation computed tomography (SRCT) of carbon fiber composite laminates reveals the first-ever qualitative and quantitative comparisons of 3D progressive damage effects introduced by two mechanical enhancement technologies: aligned nanoscale fiber interlaminar reinforcement and thin-ply layers. The technologies were studied individually and in combination, using aerospace-grade unidirectional prepreg standard-thickness (‘std-ply’) and thin-ply composite laminates. The relatively weak interlaminar regions of the laminates were reinforced with high densities of aligned carbon nanotubes (A-CNTs) in a hierarchical architecture termed ‘nanostitching’. Quasi-isotropic double edge-notched tension (DENT) laminates were tested and simultaneously 3D-imaged via SRCT at various load steps, revealing a progressive 3D network of damage micro-mechanisms that were segmented according to modality and extent. For load steps of 0%, 70%, 80%, and 90% of baseline ultimate tensile strength (UTS), intralaminar matrix cracking and fiber/matrix interfacial debonding are found to be the dominant damage mechanisms, common to all laminate types. For both std-ply and thin-ply, nanostitched laminates had qualitatively and quantitatively similar matrix damage modality and extent compared to the baseline laminates through 90% UTS, including relatively few delaminations, despite an ~9% increase in std-ply nanostitched UTS over the std-ply baseline. Complementary finite element-based modeling of damage predicts greater delamination extent in std-ply vs. thin-ply laminates that manifests only between 90% and 100% UTS, offering an explanation for the observed positive nanostitch effect in the std-ply, which is known to be more susceptible to delamination formation and growth than the thin-ply laminates. Thin-ply, with and without nanostitch, intrinsically suppresses matrix damage, as expected from past work and evidenced here by 6.5X less overall matrix damage surface area vs. std-ply baseline laminates averaged over all load steps. These findings contribute new insights from high-resolution experimental mapping of composite damage states that can guide and inform mechanical enhancement approaches and improved damage models.

Deep learning based low-dose synchrotron radiation CT reconstruction

Synchrotron radiation sources are widely used in various fields, among which computed tomography (CT) is one of the most important. The amount of effort expended by the operator varies depending on the subject. If the number of angles needed to be used can be greatly reduced under the condition of similar imaging effects, the working time and workload of the experimentalists will be greatly reduced. However, decreasing the sampling angle can produce serious artifacts and blur the details. We try to use a deep learning model which can build high quality reconstruction sparse data sampling from the angle of the image and ResAttUnet are put forward. ResAttUnet is roughly a symmetrical U-shaped network that incorporates similar mechanisms to ResNet and attention. In addition, the mixed precision is adopted to reduce the demand for video memory of the model and training time.

Data rich imaging approaches assessing fatigue crack initiation and early propagation in a DS superalloy at room temperature

Crack initiation and early propagation behavior of the directionally solidified (DS) superalloy CM247LC has been assessed by data rich imaging approaches. These include conventional characterization methods such as replica record analysis, 3D optical surface imaging, optical and scanning electron microscopy (SEM) as well as more recent techniques like digital image correlation (DIC) and synchrotron radiation computed tomography (SRCT). Three modes of secondary crack behaviors were found during evaluation of the fatigue process. The early stages of fatigue damage were controlled by microstructure-induced cracking, mainly consisting of carbide cracking. Fatigue damage was then promoted via slip band cracking and opening mode controlled carbide-cracking. The mechanisms of these different cracking behaviors are associated with the plastic zone of the main crack tip. Even though the early localized strain levels were of the same intensity within slip bands and at the intersection sites with carbides, carbide-induced cracking occurred prior to slip band cracking, characterized by SEM-DIC. This indicated that carbide-induced cracking was more likely to occur in the early stages of the fatigue process. Early crack growth behaviors were further investigated in situ at the microstructural scale via SRCT. The effect of carbides on crack initiation and propagation processes were evaluated in 3D. This revealed the phenomenon around pores, that cracks simultaneously grew on different slip planes in 3D, contrary to previous theories that such cracks tend to grow on a single favourable slip plane (in polycrystalline alloys). The SRCT result demonstrates the importance and necessity of 3D characterization of the crack propagation behavior at sub-surface, which is not fully analyzed by 2D characterization.

Damage evolution of 3D woven carbon/epoxy composites under tension-tension fatigue loading based on synchrotron radiation computed tomography (SRCT)

A method combining mechanical testing, infrared thermography (IRT) and synchrotron radiation computed tomography (SRCT) is proposed for the damage evolution of 3D woven carbon/epoxy composites under tension-tension (T-T) fatigue loading. To study the relationship between the damage evolution and the stiffness degradation, fatigue tests of six specimens are carried out to different stages before detection by SRCT and optical microscope. The detected results have revealed how cracks initiate, distribute and develop with increasing fatigue cycles. Particularly, the effects of fiber yarn undulation and twist caused during the manufacturing process are discussed.

Application of Synchrotron Radiation–Computed Tomography In-Situ Observations and Digital Volume Correlation to Study Low-Cycle Fatigue Damage Micromechanisms in Lost Foam Casting A319 Alloy

The synchrotron radiation–computed tomography (SR-CT) and digital volume correlation (DVC) methods were used to investigate the damage micromechanisms of lost foam casting (LFC) A319 alloy in low-cycle fatigue (LCF). LCF tests with SR-CT in-situ observations allow visualizing the damage evolution process in the bulk. DVC measures the mechanical fields and, thus, allows establishing the relations between crack initiation and propagation, mechanical fields, and microstructure. Cracks initiate at and propagate along hard inclusions due to strain localizations. The damage process, i.e., crack initiation and propagation, can be considered as a series of failure events of hard inclusions under strain localizations. The pores’ size, shape, location, and number were observed to have an influence on crack initiation, while the interconnected hard inclusion networks guarantee the continuous failure events of hard inclusions and, thus, provide crack propagation paths.

Comparison of propagation-based CT using synchrotron radiation and conventional cone-beam CT for breast imaging.

To evaluate and compare the image quality of propagation-based phase-contrast computed tomography (PB-CT) using synchrotron radiation and conventional cone-beam breast computed tomography (CBBCT) based on various radiological image quality criteria. Eight excised breast tissue samples of various sizes and containing different lesion types were scanned using PB-CT at a synchrotron facility and using CBBCT at a university-affiliated breast imaging centre. PB-CT scans were performed at two different mean glandular dose (MGD) levels: standard (5.8 mGy) and low (1.5 mGy), for comparison with CBBCT scans at the standard MGD (5.8 mGy). Image quality assessment was carried out using six quality criteria and six independent medical imaging experts in a reading room with mammography workstations. The interobserver agreement between readers was evaluated using intraclass correlation coefficient (ICC), and image quality was compared between the two breast imaging modalities using the area under the visual grading characteristic curve (AUCVGC). Interobserver agreement between the readers showed moderate reliability for five image criteria (ICC: ranging from 0.488 to 0.633) and low reliability for one criterion (image noise) (ICC 0.307). For five image quality criteria (overall quality, perceptible contrast, lesion sharpness, normal tissue interfaces, and calcification visibility), both standard-dose PB-CT images (AUCVGC 0.958 to 1, p ≤ .05) and low dose PB-CT images (AUCVGC 0.785 to 0.834, p ≤ .05) were of significantly higher image quality than standard-dose CBBCT images. Synchrotron-based PB-CT can achieve a significantly higher radiological image quality at a substantially lower radiation dose compared with conventional CBBCT. • PB-CT using synchrotron radiation results in higher image quality than conventional CBBCT for breast imaging. • PB-CT using synchrotron radiation requires a lower radiation dose than conventional CBBCT for breast imaging. • PB-CT can help clinicians diagnose patients with breast cancer.

Analysis on Bone Microstructure for Osteonecrosis of the Femoral Head by Synchrotron Radiation CT

Analysis on Bone Microstructure for Osteonecrosis of the Femoral Head by Synchrotron Radiation CT

Complementary ex situ investigations of various fracture modes in a single-edge-notched symmetric cross-ply laminate subjected to tensile loading

Abstract In situ experimentation using synchrotron radiation computed tomography (SRCT) is instrumental to observe subsurface mechanical behavior of composite materials in real time. However, the investigation areas of SRCT are often limited by its experimental configurations. In the present study, an ex situ observation is carried out to complement the in situ test results reported previously in the literature. Previous SRCT-based in situ experiment on the single-edge-notched symmetric cross-ply laminate has visualized various failure modes at the notch, which are sequentially occurring inside the specimen. The tested specimen is further examined here using a laboratory-scale X-ray CT device with a dye penetrant. Delamination failures interacting with longitudinal and transverse cracks, which have not been detected by the in situ test, are found with other failure modes distributed over the entire specimen area. The ex situ and in situ experimental results are complementary and both of them are required to comprehensively understand the various and complex failure mechanisms of the composite.

In situ observation of interactive failure modes in a single-edge notched symmetric cross-ply laminate using synchrotron X-ray tomography

Interactive failure mechanisms of a single-edge notched (SEN) symmetric cross-ply laminate subjected to tensile loading are studied in situ using synchrotron X-ray tomography and a DIC technique at the micro- and macro-scales. The SEN configuration guarantees the repeatability and consistency of the progressive and interactive failure behavior at the two different scales. The evolution of various fracture modes in different layers is observed through synchrotron radiation CT images. Due to the geometrically asymmetric configuration, all the initial cracks sequentially occurring near the notch tip can be captured in a narrow field of view. Stress relaxation due to the subsequent fracture initiations is indirectly captured by measuring the crack lengths and opening displacements from the 3D CT images at different loading steps. The stress relaxation is directly measured by DIC analysis using the macro-scale test data. DIC results show strains relaxed in the region between existing and emerging transverse cracks.

In Situ Testing Using Synchrotron Radiation Computed Tomography in Materials Research

ABSTRACTHigh resolution (< 1 µm) computed tomography is an attractive tool in materials research due to its ability to non-destructively visualize the three-dimensional internal microstructures of the material. Recently, this technique has been further empowered by adding a fourth (temporal) dimension to study the time-lapse material response under load. Such studies are referred to as four-dimensional or in situ testing. In this snapshot review, we highlight three representative examples of in situ testing using synchrotron radiation computed tomography (SRCT) for composites failure analysis, measurement of local corrosion rate in alloys, and visualization and quantification of electrochemical reactions in lithium-ion batteries, as well as forward-looking integration of machine learning with in situ CT. Lastly, the future opportunities and challenges of in situ SRCT testing are discussed.

Numerical simulations of NMR relaxation in chalk using local Robin boundary conditions.

The interpretation of nuclear magnetic resonance (NMR) data is of interest in a number of fields. In Ögren (2014) local boundary conditions for random walk simulations of NMR relaxation in digital domains were presented. Here, we have applied those boundary conditions to large, three-dimensional (3D) porous media samples. We compared the random walk results with known solutions and then applied them to highly structured 3D domains, from images derived using synchrotron radiation CT scanning of North Sea chalk samples. As expected, there were systematic errors caused by digitalization of the pore surfaces so we quantified those errors, and by using linear local boundary conditions, we were able to significantly improve the output. We also present a technique for treating numerical data prior to input into the ESPRIT algorithm for retrieving Laplace components of time series from NMR data (commonly called T-inversion).

In situ statistical measurement of local morphology in carbon-epoxy composites using synchrotron X-ray computed tomography

Models are still deficient in accurately reproducing the mechanisms that trigger tensile failure in unidirectional composites, highlighting a lack of direct experimental evidence. In this study, emphasis is given to the identification of connections between local fibre misorientation, packing and Weibull strength distribution in causing tensile failure. Synchrotron Radiation Computed Tomography (SRCT) and automated image processing techniques are adopted to segment individual fibres from loaded carbon fibre coupons. Subtle indications in the misorientation of local damaged sites are assessed in novel statistical detail for systematic differentiation from non-damaged sites. It is observed that the morphology of the surrounding environment of damaged sites statistically differs from that of non-damaged sites, even though locally damaged sites (containing single or coupled breaks) do not exhibit a peculiar fibre packing arrangement. For adjacent coupled breaks, the statistical nature of fibre separation distances is also reported.

Regional Behavior of Airspaces During Positive Pressure Reduction Assessed by Synchrotron Radiation Computed Tomography.

IntroductionThe mechanisms of lung inflation and deflation are only partially known. Ventilatory strategies to support lung function rely upon the idea that lung alveoli are isotropic balloons that progressively inflate or deflate and that lung pressure/volume curves derive only by the interplay of critical opening pressures, critical closing pressures, lung history, and position of alveoli inside the lung. This notion has been recently challenged by subpleural microscopy, magnetic resonance, and computed tomography (CT). Phase-contrast synchrotron radiation CT (PC-SRCT) can yield in vivo images at resolutions higher than conventional CT.ObjectivesWe aimed to assess the numerosity (ASden) and the extension of the surface of airspaces (ASext) in healthy conditions at different volumes, during stepwise lung deflation, in concentric regions of the lung.MethodsThe study was conducted in seven anesthetized New Zealand rabbits. They underwent PC-SRCT scans (resolution of 47.7 μm) of the lung at five decreasing positive end expiratory pressure (PEEP) levels of 12, 9, 6, 3, and 0 cmH2O during end-expiratory holds. Three concentric regions of interest (ROIs) of the lung were studied: subpleural, mantellar, and core. The images were enhanced by phase contrast algorithms. ASden and ASext were computed by using the Image Processing Toolbox for MatLab. Statistical tests were used to assess any significant difference determined by PEEP or ROI on ASden and ASext.ResultsWhen reducing PEEP, in each ROI the ASden significantly decreased. Conversely, ASext variation was not significant except for the core ROI. In the latter, the angular coefficient of the regression line was significantly low.ConclusionThe main mechanism behind the decrease in lung volume at PEEP reduction is derecruitment. In our study involving lung regions laying on isogravitational planes and thus equally influenced by gravitational forces, airspace numerosity and extension of surface depend on the local mechanical properties of the lung.

Microstructure-based multi-scale evaluation of fluid flow in an anthracite coal sample with partially-percolating voxels

Understanding fluid flow behavior in coal is of great significance for coal-bed methane exploration. X-ray CT and image segmentation have been widely used to extract pore network and generate flow field grids for flow simulation in coal samples. However, these techniques have fundamental limitations for the multi-scale characterization of coal samples, where the sub-voxel scale details could not be resolved for millimeter scale macroscopic samples. This makes it difficult to simulate the multi-scale flow behavior of fluid transport in coal sample with varying pore scales. The primary challenge is to make connection between simulation results of different scales. In the present work, multi-scale fluid flow in an anthracite coal sample was simulated by incorporating the data-constrained modeling (DCM), molecular dynamics (MD) method and partially-percolating lattice Boltzmann method (PP-LBM). In this multi-scale simulation method, three-dimensional (3D) flow field containing multi-scale structural information of the coal sample was generated by combining DCM with multi-energy synchrotron radiation CT. Multi-scale fluid flow was simulated by PP-LBM. In PP-LBM, an effective percolation fraction parameter which represents the effective volume fraction of the fluid that contributed to the flow for the voxel was used as a bridge to connect the fluid flow pattern of sub-voxel scales and voxel scales. The effective percolation fraction of a voxel versus its porosity was derived by MD simulations at the sub-voxel size level. The 3D distribution of fluid speed in the coal sample and its permeability were obtained by this multi-scale method. The numerical results are consistent with published laboratory measurements. Our proposed approach incorporated multi-scale effects and offered a more realistic fluid transport simulation method for a coal sample with varying pore size scales from the microscopic to macroscopic level. The method would be applicable for fluid transport simulations for other multi-scale porous materials.

Evaluation of liver iron content using synchrotron radiation CT in iron-overload mice

Evaluation of liver iron content (LIC) is crucial for the judgment of hepatic iron overload (HIO). Here, we evaluated the potential utility of synchrotron radiation (SR) CT for quantifying LIC in mice suffered from HIO. The mice models of HIO were made by the injection of iron dextran. A series of total iron injection doses of 0, 12.5, 25, 50 and 100 mg were used. SR CT imaging was performed using a detector with the pixel size of 6.5 μm × 6.5 μm at the energy level of 12 keV . The iron micro-depositions were pathologically confirmed using Prussian blue staining. The reconstructed transverse sections were obtained by applying the filtered back projection (FBP) algorithm with PITRE software. 3D visualization was performed using Amira 5.4. LIC was confirmed by an inductively coupled plasma (ICP) spectrometer. SR CT-derived LIC (LICCT) was defined as the volume ratio of iron depositions to the liver. The volume ratio was measured using ImageJ software. SR CT presented a high-spatial resolution to clearly display iron micro-depositions in the iron-overload liver. Additionally, iron micro-depositions were found to distribute unevenly on 3D images. The LICCTs were 0, (1.890 ± 0.172)%, (4.148± 0.282)%, (6.769± 0.201)%, and (12.912 ± 0.270)% for injection doses of 0 mg, 12.5 mg, 25 mg, 50 mg and 100 mg, respectively. LICCT had a strong linear correlation with injection dose (R02= 0.993, P< 0.0001) or ICP-derived LIC (LICICP) (R2 = 0.9644, P < 0.0001). The linear correlation between LICCT and LICICP could be expressed by an equation. Using this equation, LIC could be predicted by measuring LICCT. Therefore, SR CT imaging showed potential ability to quantify LIC. The imaging modality may be used for the evaluation of disease progression and therapeutic efficacy in mice models.

Synchrotron radiation computed tomography assessment of calcified plaques and coronary stenosis with different slice thicknesses and beam energies on 3D printed coronary models.

To investigate the effect of different slice thicknesses and beam energies on the visualization and assessment of coronary artery stenosis caused by calcified plaques using synchrotron radiation computed tomography (CT) based on 3D printed coronary artery models. Patient-specific 3D coronary models were created based on 3 sample coronary CT angiographic cases with calcified plaques in the left coronary arteries. In addition to the original significant coronary stenosis (>70%) shown on these CT images, stenoses of <50% and >90% were created in the segmented coronary models for simulation of different degrees of stenosis. The coronary lumen and calcification were printed with soft and rigid materials to simulate properties of coronary wall and calcified plaque, respectively. The models were scanned with synchrotron radiation CT with beam energies of 30, 40 and 50 keV and spatial resolution of 0.019×0.019×0.019 mm3 voxel size. Original high-resolution images were reconstructed with slice thicknesses of 0.095, 0.208, 0.302 and 0.491 mm to determine the effect of spatial resolution on plaque and coronary stenosis assessment based on 2D axial and 3D virtual intravascular endoscopy (VIE) images. Three coronary artery models were successfully printed with plaques placed in the coronary arteries to simulate different degrees of stenosis. 2D and 3D VIE images reconstructed with slice thicknesses of 0.095, 0.208 and 0.302 mm allowed for accurate assessment of coronary plaques and lumen stenosis with no significant differences (P>0.05). Synchrotron radiation CT images reconstructed with a slice thickness of 0.491 mm resulted in overestimation of coronary stenosis when compared to other images on 2D and 3D VIE views (<50% vs. 55-72%; 70-79% vs. 80-90%) with significant differences (P<0.05). Similarly, irregular plaque appearances were observed on 2D and 3D VIE images with a slice thickness of 0.491 mm when compared to others using thin slice thicknesses. The scanning protocol with beam energy of 30 keV provided optimal visualization of coronary lumen and plaque appearances. This study shows the feasibility of using 3D printed coronary artery models to simulate calcifications and different degrees of coronary stenosis. High resolution synchrotron radiation CT imaging with the 30 keV beam energy enables accurate assessment of coronary stenosis in the presence of calcification, thus highlighting the importance of high spatial resolution in the diagnosis of calcified coronary plaques.

153 Dose monitoring in synchrotron radiation breast computed tomography with radiochromic films

Purpose To measure the dose distribution in a phantom during a synchrotron radiation (SR) computed tomography (CT) scan using radiochromic films, for procedure assessment and for offline dose monitoring in SR breast CT. Methods We used XR-QA2 radiochromic films (calibrated in terms of free air kerma) and a 14-cm PMMA cylindrical phantom. Measurements were performed at the SYRMEP beamline of ELETTRA facility, within the SYRMA-3D project for phase-contrast breast CT [1] . The phantom was positioned at isocenter, pending from the patient bed. Measurements were performed at 38 keV, beam size of 3 mm × 150 mm (H × W), at an air kerma corresponding to a mean glandular dose of 5 mGy in a 14-cm diameter 50% glandular breast. The phantom was irradiated over 360° first with a film at the mid-plane, and then with film strips wrapped on its surface. Additional tests were made over 180° with an axial scan pitch of 1, 0.8 or 0.5. Results Results show a dose map at mid-plane the phantom, indicating the cup-shaped horizontal profile due to primary and scatter dose. Analogous maps were recorded with the films at the periphery of the phantom, representing the surface dose maps. Conclusions We performed measurements of the dose distribution in a phantom during a SR CT scan with different irradiation geometries. This technique produces evidence for selecting the suitable scan procedure. Moreover, as an offline monitor system, a piece of calibrated radiochromic film wrapped on a suitable holder around the breast could record the history of the organ irradiation.

Multi-contrast diffraction enhanced computed laminography at Beijing Synchrotron Radiation Facility.

Synchrotron radiation X-ray computed tomography (CT) enables nondestructive visualization of 3D morphological and chemical changes inside a sample and has become a powerful analysis tool to monitor reactive parts and their chemical states. However, synchrotron radiation CT imaging of specimens with lateral extensions much larger than the acceptance window of detectors is rather problematic due to strong absorption of X-rays in the lateral directions. On the other hand, X-ray computed laminography (CL) permits 3D imaging of flat samples while X-ray diffraction enhanced imaging (DEI) can provide high-quality results with different imaging contrasts such as absorption, phase and dark-field for samples with weak absorptions. Combining CL and DEI together, we have developed a multi-contrast DEI-CL system at the 4W1A beamline of the Beijing Synchrotron Radiation Facility for this kind of sample. Here we reported its design, implementation, and preliminary experimental results of carbon fiber reinforced polymer laminates with three kinds of imaging contrasts. The results have demonstrated the validity of this DEI-CL system. It will be helpful to push the applications of the state-of-the-art synchrotron radiation methods and instruments towards cutting-edge research. Graphical abstract ᅟ.

Significant dose reduction using synchrotron radiation computed tomography: first clinical case and application to high resolution CT exams

Since the invention of Computed Tomography (CT), many technological advances emerged to improve the image sensitivity and resolution. However, no new source types were developed for clinical use. In this study, for the first time, coherent monochromatic X-rays from a synchrotron radiation source were used to acquire 3D CTs on patients. The aim of this work was to evaluate the clinical potential of the images acquired using Synchrotron Radiation CT (SRCT). SRCTs were acquired using monochromatic X-rays tuned at 80 keV (0.350 × 0.350 × 2 mm3 voxel size). A quantitative image quality comparison study was carried out on phantoms between a state of the art clinical CT and SRCT images. Dedicated iterative algorithms were developed to optimize the image quality and further reduce the delivered dose by a factor of 12 while keeping a better image quality than the one obtained with a clinical CT scanner. We finally show in this paper the very first SRCT results of one patient who received Synchrotron Radiotherapy in an ongoing clinical trial. This demonstrates the potential of the technique in terms of image quality improvement at a reduced radiation dose for inner ear visualization.

Synchrotron radiation computed tomography versus conventional computed tomography for assessment of four types of stent grafts used for endovascular treatment of thoracic and abdominal aortic aneurysms.

To determine the accuracy of synchrotron radiation computed tomography (CT) for measurement of stent wire diameters for in vitro simulation of endovascular aneurysm repair by four different types of stent grafts when compared to conventional CT images. This study was performed using an aorta model with implantation of four aortic stent grafts for endovascular treatment of thoracoabdominal and abdominal aortic aneurysms. The aorta model was scanned using synchrotron radiation CT with beam energies ranging from 60 to 90 keV with 10 keV increment at each scan and spatial resolution of 41.6 µm per pixel. Stent wire diameters were measured at the top and body regions of each stent graft based on 2-dimensional (2D) axial and 3-dimensional (3D) reconstruction images, with measurements compared to those obtained from 128-slice CT images which were acquired with slice thickness of 0.5 mm. Synchrotron radiation CT images clearly demonstrated stent graft details with accurate assessment of stent wire diameters, with measurements at the top of stent grafts (between 0.32±0.02 and 0.47±0.02 mm) similar to the actual diameters (between 0.32±0.01 and 0.48±0.01 mm) when the beam energies of 70 and 80 keV were used, regardless of the types of stent grafts assessed. A beam energy of 60 keV resulted in stent wires thicker than the actual sizes, although this did not reach statistical significance (P=0.07-0.29), while the beam energy of 90 keV led to stent wires smaller than the actual sizes at the top (P=0.16) and body region (P=0.02) of stent grafts on 2D axial images. The stent wire sizes measured at the body region of stent grafts on 3D synchrotron radiation images (between 0.19±0.02 and 0.43±0.02 mm) were significantly smaller than the actual diameters (P=0.02-0.04). Stent wires were overestimated on conventional CT images with diameters more than 2-fold larger than the actual sizes (P=0.007-0.03) at both top and body regions of all four stent grafts. This study further confirms the accuracy of high-resolution synchrotron radiation CT in image visualization and size measurement of different aortic stent grafts with measured wire diameters similar to the actual ones, thus allowing for more accurate assessment of stent wire details for endovascular repair of aortic aneurysms.