Contrast X-ray Imaging Research Articles

Multifunctional Cu2-xTe Nanocubes Mediated Combination Therapy for Multi-Drug Resistant MDA MB 453.

Hypermethylated cancer populations are hard to treat due to their enhanced chemo-resistance, characterized by aberrant methylated DNA subunits. Herein, we report on invoking response from such a cancer lineage to chemotherapy utilizing multifunctional copper telluride (Cu2−XTe) nanocubes (NCs) as photothermal and photodynamic agents, leading to significant anticancer activity. The NCs additionally possessed photoacoustic and X-ray contrast imaging abilities that could serve in image-guided therapeutic studies.

EVITA Project: Comparison Between Traditional Non-Destructive Techniques and Phase Contrast X-Ray Imaging Applied to Aerospace Carbon Fibre Reinforced Polymer

The EU-project EVITA (Non-Destructive EValuation, Inspection and Testing of Primary Aeronautical Composite Structures Using Phase Contrast X-Ray Imaging) aims at bringing Grating-based Phase Contrast X-ray imaging technology to Non-Destructive Evaluation and Inspection of advanced primary and/or complex aerospace composite structures. Grating-based Phase Contrast X-Ray Imaging is based on the so-called Talbot-Lau interferometer, which is made of the combination of a standard X-ray apparatus with three transmission gratings as documented in the literature. This paper presents a comparison of two traditional non-destructive techniques (NDT): ultrasonic through transmission (immersed and water jet) and ultrasonic phased-array pulse echo, with the developed phase contrast X-Ray Imaging applied to advanced aerospace carbon fibre reinforced polymer. Typical defects produced during manufacture is examined as part of the testing and validation procedure. The following defects have been identified as being those most likely to be detected more effectively by the Grating-based Phase Contrast X-Ray Imaging process than other state of the art industrial NDT techniques: porosity, foreign objects, cracks, resin rich, cut fibres, and wavy fibres. The introduction of this innovative methodology is expected to provide the aeronautical industry with a reliable and detailed insight of the integrity of thin and thick composite structures as well as of complex geometry ones, such as integrated closed boxes and sandwiches.

Synchrotron Tomographic Images From Mixed Ground Glass Opacity of Human Lung Adenocarcinoma and Histologic Correlations

SESSION TITLE: Lung Cancer II SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, October 26, 2016 at 01:30 PM - 02:30 PM PURPOSE: High resolution tomographic images using synchrotron X-rays are expected to provide reflection for microstructure in detail, thereby to examine the histologic structure without destructing the specimen. This study aims to evaluate the synchrotron tomographic images of mixed ground glass opacity excised on 5mm section in comparison of pathologic examination. METHODS: Phase contrast X-ray images of human lung adenocarcinoma were obtained from the multiple Wiggler beam line 6C at the Pohang Light Source (PLS) in Korea. The X-ray emanated from a bending magnet of the electron storage ring with an electron energy of 2.5 GeV, and a typical beam current was 320mA. Visual images were magnified using 2X and 5X microscope lens, and the distance between the sample and the detector were 85cm and 50cm respectively. Reconstructed tomographic images were compared with images from histologic slides which made from the identical samples. RESULTS: Pulmonary microstructure including terminal bronchiole, alveolar sac, and vasculature could be identified with phase contrast X-ray images. Images from normal lung tissue and mixed ground glass opacity were clearly distinguishable. The hyperplasia of interalveolar septum and dyplasia of microstructure were clearly identified. The imaging findings showed good correlation with those from the histologic examination which obtained from the light microscopic analysis of specimens obtained with hematoxylin-eosin. CONCLUSIONS: Tomographic images which were obtained using synchrotron radiation have the potential for clinical applications. With refinement, this technique may have been used for diagnosis of lung cancer in vivo. CLINICAL IMPLICATIONS: Synchrotron radiation has been used for various medical research including imaing and functional studies. Clinical trials for imaging studies of mammography has been performed and reported excellent results. Recently, synchrotron radiation has been adopted for the radiation therapy, and clinical trials for human brain radiation therapy has been conducted. In lung cancer research, synchrotron radiation can be used for detection of early stage lung cancers, especially for ground glass opacities, which comprises heterogeouns pathologic subtypes. DISCLOSURE: The following authors have nothing to disclose: Eunjue Yi, Sungho Lee, Jae Ho Chung, Sanghoon Jheon No Product/Research Disclosure Information

Influence of barium sulfate X-ray imaging contrast material on properties of floating drug delivery tablets

The objective of the study was to reveal the influence of necessarily added barium sulfate (BaSO4) X-ray contrast material on floating drug delivery tablets. Based on literature survey, a chosen floating tablet composition was determined containing HPMC and carbopol 943P as matrix polymers. One-factor factorial design with five levels was created for evaluation of BaSO4 (X1) effects on experimental parameters of tablets including: floating lag time, total floating time, swelling-, erosion-, dissolution-, release kinetics parameters and X-ray detected volume changes of tablets. Applied concentrations of BaSO4 were between 0 and 20.0% resulting in remarkable alteration of experimental parameters related especially to flotation. Drastic deterioration of floating lag time and total floating time could be observed above 15.0% BaSO4. Furthermore, BaSO4 showed to increase the integrity of tablet matrix by reducing eroding properties. A novel evaluation of dissolutions from floating drug delivery systems was introduced, which could assess the quantity of drug dissolved from dosage form in floating state. In the cases of tablets containing 20.0% BaSO4, only the 40% of total API amount could be dissolved in floating state. In vitro fine resolution X-ray CT imagings were performed to study the volume change and the voxel distributions as a function of HU attenuations by histogram analysis of the images. X-ray detected relative volume change results did not show significant difference between samples. After 24h, all tablets containing BaSO4 could be segmented, which highlighted the fact that enough BaSO4 remained in the tablets for their identification.

Small angle x-ray scattering with edge-illumination.

Sensitivity to sub-pixel sample features has been demonstrated as a valuable capability of phase contrast x-ray imaging. Here, we report on a method to obtain angular-resolved small angle x-ray scattering distributions with edge-illumination- based imaging utilizing incoherent illumination from an x-ray tube. Our approach provides both the three established image modalities (absorption, differential phase and scatter strength), plus a number of additional contrasts related to unresolved sample features. The complementarity of these contrasts is experimentally validated by using different materials in powder form. As a significant application example we show that the extended complementary contrasts could allow the diagnosis of pulmonary emphysema in a murine model. In support of this, we demonstrate that the properties of the retrieved scattering distributions are consistent with the expectation of increased feature sizes related to pulmonary emphysema. Combined with the simplicity of implementation of edge-illumination, these findings suggest a high potential for exploiting extended sub-pixel contrasts in the diagnosis of lung diseases and beyond.

The use of contrast enhancement techniques in X-ray imaging of lithium–ion battery electrodes

Understanding the microstructural morphology of Li–ion battery electrodes is crucial to improving the electrochemical performance of current Li–ion battery systems and in developing next-generation power systems. The use of 3D X-ray imaging techniques, which are continuously evolving, provides a non-invasive platform to study the relationship between electrode microstructure and performance at various time and length scales. In addition to characterizing a weakly (X-ray) absorbing graphite electrode at multiple length scales, we implement an approach for obtaining improved nano-scale image contrast on a laboratory X-ray microscope by combining information obtained from both absorption–contrast and Zernike phase-contrast X-ray images.

Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ∼1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.

X-ray PIV measurement of blood flow in deep vessels of a rat: An in vivo feasibility study.

X-ray PIV measurement is a noninvasive approach to measure opaque blood flows. However, it is not easy to measure real pulsatile blood flows in the blood vessels located at deep position of the body, because the surrounding tissues significantly attenuate the contrast of X-ray images. This study investigated the effect of surrounding tissues on X-ray beam attenuation by measuring the velocity fields of blood flows in deep vessels of a live rat. The decrease in image contrast was minimized by employing biocompatible CO2 microbubbles as tracer particles. The maximum measurable velocity of blood flows in the abdominal aorta of a rat model was found through comparative examination between the PIV measurement accuracy and the level of image contrast according to the input flow rate. Furthermore, the feasibility of using X-ray PIV to accurately measure in vivo blood flows was demonstrated by determining the velocity field of blood flows in the inferior vena cava of a rat. This study may serve as a reference in conducting in vivo X-ray PIV measurements of pulsatile blood flows in animal disease models and investigating hemodynamic characteristics and circulatory vascular diseases.

High Resolution Molecular Radiation Therapy and Tumor Imaging for the 21st Century

With the lightest ions beyond protons, i.e., Helium, Lithium and Beryllium ions, highly specific Molecular Bragg peak radiation therapy of malignant tumors is possible with minimal adverse normal tissue reactions elsewhere in the body. The Bragg peak ionization density is only elevated in a few mm wide spot at the end of the ion range with resultant increased local apoptosis and senescence. By only placing Bragg peaks in the tumor, an increased local therapeutic effect is obtained with only low ionization density and easily repairable damage in surrounding normal tissues. A geometrical accuracy in dose delivery of about 1 mm is possible with these ions, and high-resolution molecular tumor imaging is then needed to accurately delineate the target volume. It is proposed that ultra-sensitivity whole body PET cameras should be built to achieve mm resolution in the whole target region. With about 1 m axial field of view an almost 50-fold increased sensitivity and a reduced imaging time down to a few minutes should be in reach. To get sub mm resolution with whole body spectroscopic MR, about 15 Tesla to 20 Tesla is needed and will significantly increase the resolution with tumor specific metabolite imaging from the 10 mm to 15 mm available today. In the future, it should also be possible to achieve a resolution as high as 10 μm with Stereoscopic Phase Contrast X-ray imaging, or to reduce the dose and imaging time by using 2 projections instead of 400 to get 3D images, thanks to the significantly increased contrast in each projection. When these new methods are brought into clinical use together with light ion therapy a mean tumor cure as high as 80% should be possible, and even more if the new early tumor detection and malignancy estimation methods are brought into more regular clinical use.

放射光Ｘ線を用いた位相コントラスト法による肝蔵内血管流動特性の可視化

放射光Ｘ線を用いた位相コントラスト法による肝蔵内血管流動特性の可視化

Investigation of grid performance using simple image quality tests.

Antiscatter grids improve the X-ray image contrast at a cost of patient radiation doses. The choice of appropriate grid or its removal requires a good knowledge of grid characteristics, especially for pediatric digital imaging. The aim of this work is to understand the relation between grid performance parameters and some numerical image quality metrics for digital radiological examinations. The grid parameters such as bucky factor (BF), selectivity (Σ), Contrast improvement factor (CIF), and signal-to-noise improvement factor (SIF) were determined following the measurements of primary, scatter, and total radiations with a digital fluoroscopic system for the thicknesses of 5, 10, 15, 20, and 25 cm polymethyl methacrylate blocks at the tube voltages of 70, 90, and 120 kVp. Image contrast for low- and high-contrast objects and high-contrast spatial resolution were measured with simple phantoms using the same scatter thicknesses and tube voltages. BF and SIF values were also calculated from the images obtained with and without grids. The correlation coefficients between BF values obtained using two approaches (grid parameters and image quality metrics) were in good agreement. Proposed approach provides a quick and practical way of estimating grid performance for different digital fluoroscopic examinations.

Low dose high energy x-ray in-line phase sensitive imaging prototype: Investigation of optimal geometric conditions and design parameters.

The objective of this study was to investigate the optimization of a high energy in-line phase sensitive x-ray imaging prototype under different geometric and operating conditions for mammography application. A phase retrieval algorithm based on phase attenuation duality (PAD) was applied to the phase contrast images acquired by the prototype. Imaging performance was investigated at four magnification values of 1.67, 2, 2.5 and 3 using an acrylic edge, an American College of Radiology (ACR) mammography phantom and contrast detail (CD) phantom with tube potentials of 100, 120 and 140 kVp. The ACR and CD images were acquired at the same mean glandular dose (MGD) of 1.29 mGy with a computed radiography (CR) detector of 43.75 μm pixel pitch at a fixed source to image distance (SID) of 170 cm. The x-ray tube focal spot size was kept constant as 7 μm while a 2.5 mm thick aluminum (Al) filter was used for beam hardening. The performance of phase contrast and phase retrieved images were compared with computer simulations based on the relative phase contrast factor (RPF) at high x-ray energies. The imaging results showed that the x-ray tube operated at 100 kVp under the magnification of 2.5 exhibits superior imaging performance which is in accordance to the computer simulations. As compared to the phase contrast images, the phase retrieved images of the ACR and CD phantoms demonstrated improved imaging contrast and target discrimination. We compared the CD phantom images acquired in conventional contact mode with and without the anti-scatter grid using the same prototype at 1.295 mGy and 2.59 mGy using 40 kVp, a 25 μm rhodium (Rh) filter. At the same radiation dose, the phase sensitive images provided improved detection capabilities for both the large and small discs, while compared to the double dose image acquired in conventional mode, the observer study also indicated that the phase sensitive images provided improved detection capabilities for the large discs. This study therefore validates the potential of using high energy phase contrast x-ray imaging to improve lesion detection and reduce radiation dose for clinical applications such as mammography.

Phase contrast x-ray velocimetry of small animal lungs: optimising imaging rates.

Chronic lung diseases affect a vast portion of the world's population. One of the key difficulties in accurately diagnosing and treating chronic lung disease is our inability to measure dynamic motion of the lungs in vivo. Phase contrast x-ray imaging (PCXI) allows us to image the lungs in high resolution by exploiting the difference in refractive indices between tissue and air. Combining PCXI with x-ray velocimetry (XV) allows us to track the local motion of the lungs, improving our ability to locate small regions of disease under natural ventilation conditions. Via simulation, we investigate the optimal imaging speed and sequence to capture lung motion in vivo in small animals using XV on both synchrotron and laboratory x-ray sources, balancing the noise inherent in a short exposure with motion blur that results from a long exposure.

B14-O-04X-Ray Microscopy and Microtomography at SPring-8

X-ray microscopy and microtomography have been continuously developed to realize two-/three-dimensional microimaging with a spatial resolution beyond the optical microscopy. Scanning microscopy and imaging microscopy using a Fresnel zone plate (FZP) as an x-ray optical device have been achieved the spatial resolution of better than 100 nm, and high-resolution computed tomography (CT) using such x-ray optical systems are now routinely available with the spatial resolution of better then 200 nm. Figure 1 shows the x-ray CT image of the asteroid “Itokawa” sample recovered by the spacecraft “Hayabusa”[1]. A phase-contrast x-ray imaging has also been developed. In the x-ray region, sensitivity of the phase-contrast imaging is about 1000 times higher at most for the low-Z materials than that of the absorption contrast imaging. Therefore, the phase-contrast microscope CT is frequently used for the biological samples and organic. Figure 2 shows the phase contrast x-ray CT image of human hair [2]. A novel system combining the scanning microscope and the imaging microscope has been developed for the purpose of a 3D multimodal imaging of the phase and absorption contrast x-ray imaging. In the conference, present status and some applications of x-ray microscopy at the SPring-8 public beamlines will be presented. [1] A. Tsuchiyama et al, Science 333 (2011) 1125-1128. [2] A. Takeuchi et al, AIP Conf. Proc. 1266 (2010) 42-46. Fig. 1. CT image of

X-ray specks: low dose in vivo imaging of lung structure and function

Respiratory health is directly linked to the structural and mechanical properties of the airways of the lungs. For studying respiratory development and pathology, the ability to quantitatively measure airway dimensions and changes in their size during respiration is highly desirable. Real-time imaging of the terminal airways with sufficient contrast and resolution during respiration is currently not possible. Herein we reveal a simple method for measuring lung airway dimensions in small animals during respiration from a single propagation-based phase contrast x-ray image, thereby requiring minimal radiation. This modality renders the lungs visible as a speckled intensity pattern. In the near-field regime, the size of the speckles is directly correlated with that of the dominant length scale of the airways. We demonstrate that Fourier space quantification of the speckle texture can be used to statistically measure regional airway dimensions at the alveolar scale, with measurement precision finer than the spatial resolution of the imaging system. Using this technique we discovered striking differences in developmental maturity in the lungs of rabbit kittens at birth.

Femtosecond laser-driven intense Cu K α X-ray source with a novel film target driver

A laser-induced intense Ka hard X-ray source was developed by using a novel copper film target and a 27-TW femtosecond laser system. A specially designed pinhole camera was employed to measure the X-ray photon flux, X-ray energy spectrum, and X-ray source image. By adapting a single photon counting method, we estimated the photon number in the full width at half maximum (FWHM) spectral region to be 1.74 × 109 photons/sr for 8.05-keV Cu Ka X-rays. The shape of the X-ray source was matched well with that of the focused laser beam on the target. By provision of a lengthy copper film of 50 m with a thickness of 50 µm, the novel copper film target is capable of long time operation of more than 27 hours at a repetition rate of 10 Hz. The hard X-ray source is suitable for applications in single-shot X-ray contrast imaging or in ultrafast pump-probe analyses of material structures.

Microfocus X-ray imaging of Brazil nuts for quality control

Non-destructive quality assessment of food prior to processing is desirable in commercial facilities due to its non-invasive nature, for economic reasons and for its safety appeals. Grading Brazil nuts in this way allows for the separation of undesirable nuts to avoid contamination during the automatic nut-shelling process. The aim of this study was to evaluate the feasibility of X-ray phase contrast enhanced imaging in assessing nut quality . For this goal, details of the imaging technique are described and phase contrast X-ray and microtomography imaging of nut samples are investigated. Both high quality (i.e. “sound”) nuts as well as treated nuts were examined. It was concluded that both the X-ray imaging and tomography techniques have the potential to discriminate morphological features of the nut and to identify “sound” kernels from atypical ones. Larger nuts and nuts with a larger gap area between shell and kernel were concluded to have more atypical formations. Both techniques also seemed promising for use in automatic sorting lines. However, by using microtomography, the visualization of finer formations not noticeable in the X-ray images was possible. Further studies shall be carried out to investigate the nature of these formations, how they affect nut quality and their evolution with storage time.

Factors influencing real time internal structural visualization and dynamic process monitoring in plants using synchrotron-based phase contrast X-ray imaging.

Minimally invasive investigation of plant parts (root, stem, leaves, and flower) has good potential to elucidate the dynamics of plant growth, morphology, physiology, and root-rhizosphere interactions. Laboratory based absorption X-ray imaging and computed tomography (CT) systems are extensively used for in situ feasibility studies of plants grown in natural and artificial soil. These techniques have challenges such as low contrast between soil pore space and roots, long X-ray imaging time, and low spatial resolution. In this study, the use of synchrotron (SR) based phase contrast X-ray imaging (PCI) has been demonstrated as a minimally invasive technique for imaging plants. Above ground plant parts and roots of 10 day old canola and wheat seedlings grown in sandy clay loam soil were successfully scanned and reconstructed. Results confirmed that SR-PCI can deliver good quality images to study dynamic and real time processes such as cavitation and water-refilling in plants. The advantages of SR-PCI, effect of X-ray energy, and effective pixel size to study plant samples have been demonstrated. The use of contrast agents to monitor physiological processes in plants was also investigated and discussed.

Characterization of Mechanical Properties of Tissue Scaffolds by Phase Contrast Imaging and Finite Element Modeling.

In tissue engineering, the cell and scaffold approach has shown promise as a treatment to regenerate diseased and/or damaged tissue. In this treatment, an artificial construct (scaffold) is seeded with cells, which organize and proliferate into new tissue. The scaffold itself biodegrades with time, leaving behind only newly formed tissue. The degradation qualities of the scaffold are critical during the treatment period, since the change in the mechanical properties of the scaffold with time can influence cell behavior. To observe in time the scaffold's mechanical properties, a straightforward method is to deform the scaffold and then characterize scaffold deflection accordingly. However, experimentally observing the scaffold deflection is challenging. This paper presents a novel study on characterization of mechanical properties of scaffolds by phase contrast imaging and finite element modeling, which specifically includes scaffold fabrication, scaffold imaging, image analysis, and finite elements (FEs) modeling of the scaffold mechanical properties. The innovation of the work rests on the use of in-line phase contrast X-ray imaging at 20 KeV to characterize tissue scaffold deformation caused by ultrasound radiation forces and the use of the Fourier transform to identify movement. Once deformation has been determined experimentally, it is then compared with the predictions given by the forward solution of a finite element model. A consideration of the number of separate loading conditions necessary to uniquely identify the material properties of transversely isotropic and fully orthotropic scaffolds is also presented, along with the use of an FE as a form of regularization.

Phase retrieval method for in-line phase contrast x-ray imaging and denoising by regularization.

Phase contrast X-ray imaging is increasingly popular in the past decade. In order to acquire phase contrast X-ray images, different types of imaging mechanisms have been proposed. Among them, in-line phase contrast X-ray imaging shows the highest potential because of its simplicity. In the study of in-line phase contrast imaging, based on different physical assumptions, many non-iterative phase retrieval methods, such as Bronnikov method, modified Bronnikov method, phase-attenuation duality (PAD) method, single-material method, and two-material method have been proposed. The main step of the non-iterative methods is a filtering process, thus different methods involve different filter design. In this paper we showed that every filter applied in the methods listed above is indeed the minimizer of a L(2)-norm regularization problem. In addition, two methods were proposed to overcome the over smoothing problem owing to the nature of L(2)-norm regularization.