Ray Imaging Research Articles

Full-field x ray nano-imaging system designed and constructed at SSRF

Full-field x ray nano-imaging (FXNI) is one of the most powerful tools for in-situ, non-destructive observation of the inner structure of samples at the nanoscale. Owing to the high flux density of the third-generation synchrotron radiation facility, great progress is achieved for FXNI and its applications. Up to now, a spatial resolution of 20 nm for FXNI is achieved. Based on the user operation experiences over the years at the Shanghai Synchrotron Radiation Facility (SSRF) x ray imaging beamline, we know lots of user experiments will rely on a large range of spatial resolutions and fields of view (FOVs). In particular, x ray microscopes with a large FOV and a moderate spatial resolution of around 100 nm have a wide range of applications in many research fields. Driven by user requirements, a dedicated FXNI system is designed and constructed at the SSRF. This microscope is based on a beam shaper and a zone plate, with the optimized working energy range set to 8–10 keV. The experimental test results by a Siemens star pattern demonstrate that a spatial resolution of 100 nm is achieved, while an FOV of 50 μm is obtained.

Organic hyperinsulinism: radiological diagnostics and surgical treatment.

To optimize the diagnosis and surgical treatment of insulinoma and nesidioblastosis. 42 patients with organic hyperinsulinism (OH) were operated. There were 39 cases of insulinoma including 2 patients with insulinoma combined with nesidioblastosis and 3 cases of nesidioblastosis alone. Preoperative ray imaging consisted of percutaneous, endoscopic and intraoperative sonography, contrast-enhanced computed tomography, magnetic resonance imaging (MRI). Functional test included arterial-stimulated blood sampling (ASBS). Laparotomy and robot-assisted techniques were used in 22 and 20 patients. Sensitivity was 62.0%, 76.9%, 83.3%, 87.5%, 94.8% and 100% in percutaneous sonography, CT, endoscopic sonography, MRI, intraoperative sonography and ASBS respectively. Postoperative complications were observed in 14 and 6 patients after conventional and robot-assisted surgery. 2 patients died. Overall mortality was 4.8%. None patient had recurrent hypoglycemic conditions in long-term postoperative period (mean follow-up 18.7 months). Comprehensive survey allowed to define the cause of OH. Minimally invasive organ-sparing surgery has satisfactory immediate and remote results in these patients.

Method for Automated Bone Shape Correction within Bone Distraction Procedure

The method for automated bone shape correction within bone distraction procedure is presented. High precision deformation angle measurement is provided by the software for X- Ray images processing. Special BDC v.1.0.1. application is designed. The purpose of the BDC is modeling of the bone geometry structure to calculate the appropriate distraction forces. The correction procedure control is realized by the hardware of the distraction system.

Wavelet based Multilevel Sub-Band Adaptive Thresholding for Image Denoising using Modified PSO Algorithm

The image de-noising is one in all the foremost studied areas within the field of image processing. There are many ways (like communication channel, imperfect sensors, interference etc.) by which the noise may affect the image. Depending upon the nature of noise and the image many techniques has been already proposed. However for any technique it is difficult to operate on different level of noises over different kind of images (like SAR images, X- ray images, Ultrasound images etc.). The best possible solution for such cases is to use adaptive techniques. In this paper we are presenting a multilevel wavelet decomposition based adaptive thresholding technique which utilizes the modified Particle Swarm Optimization (PSO) algorithm to find out the optimal values for thresholds and level of decompositions for given objective function. The modification of PSO is done through random perturbation in particle velocities which induces small randomness in new particle position estimation. This randomness can effectively increase the particle search space, which ultimately provides a much better solution than the conventional PSO. Finally the proposed algorithm is validated by testing it over different kind of images corrupted by different values of noise.

Third-order aberration analysis of an off-axial optical system

The aberration theory applied to co-axial optical systems is extended to off-axial systems, for which third-order aberration coefficients are considered. The derived aberrations are analyzed using three-dimensional ray bundles, spot diagrams, and image charts, and classified in relation to the system symmetry. This theory is very useful for optical designers, allowing them to clarify the relationship between the structures of off-axial optical systems and the corresponding off-axial aberrations.

Technical difficulties of logging while drilling in carbonate reservoirs and the countermeasures: A case study from the Sichuan Basin

In the Sichuan Basin, carbonate reservoirs are characterized by deep burial depth and strong heterogeneity, so it is difficult to conduct structure steering, pore space reservoir tracking and trajectory control in the process of geosteering logging while drilling. In this paper, a series of corresponding techniques for structure, reservoir and formation tracking were proposed after analysis was conducted on multiple series of carbonate strata in terms of their geologic and logging response characteristics. And investigation was performed on the adaptabilities of the following logging technologies to geosteering while drilling, including gamma ray imaging while drilling, resistivity imaging while drilling, density imaging while drilling, gamma ray logging while drilling, resistivity logging while drilling, neutron logging while drilling and density logging while drilling. After while drilling information was thoroughly analyzed, the logging suites for four common types of complicated reservoirs (thin layered reservoirs, thick massive reservoirs, denuded karst reservoirs and shale gas reservoirs) were optimized, and five logging combinations suitable for different formations and reservoirs were proposed, including gamma ray logging + porosity + resistivity imaging, gamma ray logging + resistivity imaging, gamma ray logging + porosity + resistivity logging, gamma ray imaging + resistivity logging, and gamma ray logging. Field application indicates that it is of great reference and application value to use this method for the first time to summarize logging while drilling combinations for different types of carbonate reservoirs.

Optical analysis of miniature lenses with curved imaging surfaces.

Miniature cameras for consumer electronics and mobile phones have been, and continue to be, in fast development. The system level requirements, such as manufacturing cost, packaging, and sensor characteristics, impose unique challenges for optical designers. In this paper, we discuss the potential optical benefits of having a curved image surface rather than a flat one. We show that curved sensor technology allows for optically faster lens solutions. We discuss trade-offs of several relevant characteristics, such as packaging, chief ray angle, image quality, and tolerance sensitivity. A comparison of a benchmark flat field lens, and an evaluation design imaging on a curved surface and working at f/1.6, provides useful specific insights. For a given image quality, departing from a flat imaging surface does not allow significantly reducing the total length of a lens.

Wettability measurement under high P‐T conditions using X‐ray imaging with application to the brine‐supercritical CO2 system

AbstractWe present a new method for measuring wettability or contact angle of minerals at reservoir pressure‐temperature conditions using high‐resolution X‐ray computed tomography (HRXCT) and radiography. In this method, a capillary or a narrow slot is constructed from a mineral or a rock sample of interest wherein two fluids are allowed to form an interface that is imaged using X‐rays. After some validation measurements at room pressure‐temperature conditions, we illustrate this method by measuring the contact angle of CO2‐brine on quartz, muscovite, shale, borosilicate glass, polytetrafluoroethylene (PTFE or Teflon), and polyether ether ketone (PEEK) surfaces at 60–71°C and 13.8–22.8 MPa. At reservoir conditions, PTFE and PEEK surfaces were found to be CO2‐wet with contact angles of 140° and 127°, respectively. Quartz and muscovite were found to be water‐wet with contact angles of 26° and 58°, respectively, under similar conditions. Borosilicate glass‐air‐brine at room conditions showed strong water‐wet characteristics with a contact angle of 9°, whereas borosilicate glass‐CO2‐brine at 13.8 MPa and 60°C showed a decrease in its water‐wetness with contact angle of 54°. This method provides a new application for X‐ray imaging and an alternative to other methods.

Temporomandibular Eklem Görüntüleme Yöntemleri

Invention of new techniques and improvement of especially computer systems were provided better assessment of TMJ anatomy and functions. Pathophysiology of TMD was better understood with images associated clinical findings. Understanding of TMD’s improvements were caused emergence of new treatment approaches. TMJ imaging techniques can be arranged as direct radiographies, conventional tomography, panoramic radiography, kinetic X- ray imaging, arthrography, ultrasonography, computerized tomography, magnetic resonance imaging, nuclear medicine, cephalometric radiography. The technique is chosen which is best showing the pathology of hard and soft tissues, most easily accessible as equipment, the radiation dose of at least and most suitable for other contraindications. At this review, TMJ imaging techniques were summarized

형광지를 이용한 물품검사 X-선 DR 영상처리 시스템 개발

In the industrial field for product inspection needs not only on the surface of the product but also the internal components defect inspection. Generally, optical inspection is mainly used for item inspection from production process. However, this is only to check defect of surface it is difficult to perform inspection of goods internal. To overcome these limitations, Instead of optical device by using the portable X- ray DR image acquisition device system developed to obtain an image in real time at the same time and determine product defects. After obtaining the X- ray image, the inspection product within error range is passed after machine image processing. Also, the results and numbers are stored by users.

MO‐F‐CAMPUS‐J‐05: Verification for Prompt Gamma Ray Imaging During Proton Boron Fusion Therapy

Purpose:The purpose of this study is to verify the acquisition of the three dimensional single photon emission computed tomography (SPECT) image using prompt gamma ray originated from proton boron fusion therapy (PBFT).Methods:The real‐time imaging system during the PBFT was simulated to acquire the tomographic image of the prompt gamma ray from treated tumor by the proton boron reaction, using Monte Carlo simulation (MCNPX). We acquired percentage depth dose (PDD) of the proton beam in the water phantom including the boron uptake region (BUR), the energy spectra of the prompt gamma ray and tomographic image which can show treated tumor regions. The prompt gamma ray image was reconstructed using maximum likelihood estimation maximization (MLEM) reconstruction algorithm with 64 projections. In addition, in order to evaluate the reconstructed image, the image profiles between BURs were extracted from the image.Results:In the PDD results, the Bragg‐peak was amplified definitely when the proton's maximum dose level was located at the BUR. This amplification is based on the generation of alpha particles. In addition, the prompt gamma ray peak of 719 keV was observed from the energy spectrum. Through the previous process, the tomographic image of prompt gamma ray from the BUR was reconstructed. The line profile was extracted from image including BURs, and it shows high signal‐to‐noise ratio.Conclusion:We confirmed that the real‐time prompt gamma ray image during the PBFT was successfully deducted, and results of quantitative image analysis show good agreement with the original pattern of the BUR. This study first verified the imaging capability of the PBFT‐SPECT system. In conclusion, the PBFT‐SPECT system can realize the treated tumor monitoring during the PBFT.

13.3: Efficient Direct Light‐Field Rendering for Autostereoscopic 3D Displays

The rapid advancement of 3D display technologies enables consumers to enjoy the 3D world visually through various display systems such as stereoscopic, multiview, and light field displays. Unfortunately, to achieve a sufficient level of reality, the complexity of the conventional multiview rendering process increases. This may hinder mass deployment of 3D display products. This paper proposes a novel method, called direct light field rendering, which can compose the display light ray image without reconstructing all the multiview images beforehand. By interpreting 3D display as sampling in the light field domain, we attempt to directly compute only the necessary samples, and not the entire light fields or multiview images. Our proposed algorithm consists of solving linear systems of two variables, requiring remarkably low complexities.

Evaluation of a new position sensitive detector based on the plastic rod scintillators

In this work, a new gamma ray imaging system was developed. The system consisted of a plastic-based rod detector (BC400) coupled with a PMT at one side and a fan shaped 60Co gamma source having about 1 mCi activities. The experiments were done using metal plates with different thicknesses. It was found that using a suitable deconvolution method, the output gamma spectra of the system can provide useful information about the size and position of the gamma ray exposed objects.

Performance evaluation of a small CZT pixelated semiconductor gamma camera system with a newly designed stack-up parallel-hole collimator

Gamma ray imaging techniques that use a cadmium zinc telluride (CZT) or cadmium telluride (CdTe) pixelated semiconductor detectors have rapidly gained popularity as a key tool for nuclear medicine research. By using a pinhole collimator with a pixelated semiconductor gamma camera system, better spatial resolution can be achieved. However, this improvement in spatial resolution is accomplished with a decrease in the sensitivity due to the small collimator hole diameter. Furthermore, few studies have been conducted for novel parallel-hole collimator geometric designs with pixelated semiconductor gamma camera systems. A gamma camera system which combines a CZT pixelated semiconductor detector with a newly designed stack-up parallel-hole collimator was developed and evaluated. The eValuator-2500 CZT pixelated semiconductor detector (eV product, Saxonburg, PA) was selected for the gamma camera system. This detector consisted of a row of four CZT crystals of 12.8mm in length with 3mm in thickness. The proposed parallel-hole collimator consists of two layers. The upper layer results in a fourfold increase in hole size compared to a matched square hole parallel-hole collimator with an equal hole and pixel size, while the lower layer also consisted of fourfold holes size and pretty acts as a matched square hole parallel-hole collimator. The overlap ratios of these collimators were 1:1, 1:2, 2:1, 1:5, and 5:1. These collimators were mounted on the eValuator-2500 CZT pixelated semiconductor detector. The basic performance of the imaging system was measured for a 57Co gamma source (122keV). The measured averages of sensitivity and spatial resolution varied depending on the overlap ratios of the proposed parallel-hole collimator and source-to-collimator distances. One advantage of our system is the use of stacked collimators that can select the best combination of system sensitivity and spatial resolution. With low counts, we can select a high sensitivity collimator with a 1:5 or 5:1 overlap ratio. For high counts, a 1:1 overlap ratio collimator combination is the best selection at this time. In addition, if a higher system spatial resolution is needed, we can increase the spatial resolution by stacking additional thin collimators. These results demonstrate that the developed small pixelated semiconductor gamma camera system has high potential as an effective instrument for low energy gamma ray imaging.

X-ray phase contrast tomography by tracking near field speckle.

X-ray imaging techniques that capture variations in the x-ray phase can yield higher contrast images with lower x-ray dose than is possible with conventional absorption radiography. However, the extraction of phase information is often more difficult than the extraction of absorption information and requires a more sophisticated experimental arrangement. We here report a method for three-dimensional (3D) X-ray phase contrast computed tomography (CT) which gives quantitative volumetric information on the real part of the refractive index. The method is based on the recently developed X-ray speckle tracking technique in which the displacement of near field speckle is tracked using a digital image correlation algorithm. In addition to differential phase contrast projection images, the method allows the dark-field images to be simultaneously extracted. After reconstruction, compared to conventional absorption CT images, the 3D phase CT images show greatly enhanced contrast. This new imaging method has advantages compared to other X-ray imaging methods in simplicity of experimental arrangement, speed of measurement and relative insensitivity to beam movements. These features make the technique an attractive candidate for material imaging such as in-vivo imaging of biological systems containing soft tissue.

GPU-based prompt gamma ray imaging from boron neutron capture therapy.

The purpose of this research is to perform the fast reconstruction of a prompt gamma ray image using a graphics processing unit (GPU) computation from boron neutron capture therapy (BNCT) simulations. To evaluate the accuracy of the reconstructed image, a phantom including four boron uptake regions (BURs) was used in the simulation. After the Monte Carlo simulation of the BNCT, the modified ordered subset expectation maximization reconstruction algorithm using the GPU computation was used to reconstruct the images with fewer projections. The computation times for image reconstruction were compared between the GPU and the central processing unit (CPU). Also, the accuracy of the reconstructed image was evaluated by a receiver operating characteristic (ROC) curve analysis. The image reconstruction time using the GPU was 196 times faster than the conventional reconstruction time using the CPU. For the four BURs, the area under curve values from the ROC curve were 0.6726 (A-region), 0.6890 (B-region), 0.7384 (C-region), and 0.8009 (D-region). The tomographic image using the prompt gamma ray event from the BNCT simulation was acquired using the GPU computation in order to perform a fast reconstruction during treatment. The authors verified the feasibility of the prompt gamma ray image reconstruction using the GPU computation for BNCT simulations.

Performance of a new Electron-Tracking Compton Camera under intense radiations from a water target irradiated with a proton beam

We have developed an electron-tracking Compton camera (ETCC) for use in next-generation MeV gamma ray telescopes. An ETCC consists of a gaseous time projection chamber (TPC) and pixel scintillator arrays (PSAs). Since the TPC measures the three dimensional tracks of Compton-recoil electrons, the ETCC can completely reconstruct the incident gamma rays. Moreover, the ETCC demonstrates efficient background rejection power in Compton-kinematics tests, identifies particle from the energy deposit rate (dE/dX) registered in the TPC, and provides high quality imaging by completely reconstructing the Compton scattering process. We are planning the ``Sub-MeV gamma ray Imaging Loaded-on-balloon Experiment'' (SMILE) for our proposed all-sky survey satellite. Performance tests of a mid-sized (30 cm)3 ETCC, constructed for observing the Crab nebula, are ongoing. However, observations at balloon altitudes or satellite orbits are obstructed by radiation background from the atmosphere and the detector itself [1]. The background rejection power was checked using proton accelerator experiments conducted at the Research Center for Nuclear Physics, Osaka University. To create the intense radiation fields encountered in space, which comprise gamma rays, neutrons, protons, and other energetic entities, we irradiated a water target with a 140 MeV proton beam and placed a SMILE-II ETCC near the target. In this situation, the counting rate was five times than that expected at the balloon altitude. Nonetheless, the ETCC stably operated and identified particles sufficiently to obtain a clear gamma ray image of the checking source. Here, we report the performance of our detector and demonstrate its effective background rejection based in electron tracking experiments.

INTRAARTERIAL REGIONAL INFUSION TRACT IN THE DIAGNOSIS AND TREATMENT OF ACUTE PANCREATITIS

The study used the results of the examination and treatment of 41 patients with acute pancreatitis who underwent endovascular catheterization of the celiac trunk, followed by intra-regional perfusion of the pancreas. The clinical results of intra-regional perfusion of the pancreas showed efficacy in the prevention of septic complications, progression of pancreatic necrosis in patients with aseptic forms of severe pancreatitis. Create intraarterial infusion tract allows multislice spiral computed tomography celiacography in order to increase the information content ray imaging zones destruction of the pancreas.

158 The development of a series of orthotopic solid tumour models of prostate, lung and ovarian cancer using optical and X ray imaging

158 The development of a series of orthotopic solid tumour models of prostate, lung and ovarian cancer using optical and X ray imaging

A new field-of-view autotracking method based on back-projected ray image cross-correlation for online tomography reconstruction.

In general, a tomogram cannot be observed immediately after the acquisition of a series of specimen tilt images, but is instead observed after the post-processing of the tilt series alignment, which often requires a substantial amount of time. Moreover, for general specimens, the automatic acquisition of the tilt series is difficult because field-of-view tracking frequently fails as the tilt angle or specimen thickness increases.In this study, we focus on the improvement of the field-of-view autotracking technique for the purpose of online tomography reconstruction and propose a new alternative technique [1,2]. The method we proposed uses a so-called 'back-projected ray image' instead of a specimen tilt image. The back-projected ray image is a cross-section image calculated from each projection image only during reconstruction. As a result of a study on 'ray images', the quality and accuracy of the cross-correlation between a pair of neighboring ray images among the tilt series were observed to be very high compared with those between a pair of projection images. We observed that a back projected ray image reliably cross-correlates with other neighboring ray images at the position of an existing three-dimensional object. The proposed method can therefore consistently track the field-of-view, overcoming the weakness of a conventional image-matching-based method. In addition, the present method is simple, and high speed processing is expected to be achieved because fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT) algorithms can be used.We applied this method to real specimens in online experiments using a TEM and thereby demonstrated its successful performance. Online autotracking experiments with thin-section samples were used to demonstrate the effectiveness of the proposed method. The field-of-view was automatically tracked with high accuracy through a tilt angle range. Furthermore, online tomograms were obtained immediately after the last specimen tilting. With increases in the tracking speed, in situ tomographic observations for analyzing the dynamic behavior might become feasible in the future.jmicro;63/suppl_1/i23-a/DFU058F1F1DFU058F1Fig. 1.Comparison of the proposed autotracking method with the conventional PCF based alignment method using the yeast cell thin-section. a and b: Reconstructed X-Y cross-section images from tracking results at 8° increment angle with the PCF method and with the proposed method. N, nucleus; V, vacuole; NVJ, nucleus-vacuole junction. c: A reconstructed cross-section image from autotracking result at 1° increment angle with the proposed method. (scale bar: 100 nm).