X-ray Imaging Technology Research Articles

Enhancing the Sensitivity and Spatial Imaging Resolution of a Hybrid X-Ray Imaging Screen via Energy Transfer at the ZnS (Ag) and a Thermally Activated Delayed Fluorescence Interface.

Novel scintillation materials have played an indispensable role in the recent remarkable progress witnessed for X-ray imaging technology. Herein, a high-performance X-ray scintillation screen was developed based on a highly efficient hybrid system combining inorganic ZnS (Ag) with thermally activated delayed fluorescence (TADF) scintillator materials via an interfacial energy transfer (EnT) mechanism. ZnS (Ag) has a high X-ray absorption capacity and functions as the initial layer for efficiently converting high-energy X-ray photons into low-energy visible light (acting as a sensitizer) while also serving as an energy donor. The TADF component, on the contrary, is an energy acceptor and forms an active scintillating layer. By harnessing TADF chromophores that can efficiently capture both singlet and triplet excitons, our composite material offers a remarkable spatial imaging resolution of 24 line pairs per millimeter, surpassing those of the majority of existing organic and inorganic scintillators. Further, our interfacial energy transfer strategy effectively amplifies the radioluminescence intensity of the TADF scintillator by a factor of 75, offering an outstanding light yield of 38,000 photons/MeV. This advancement represents a remarkable breakthrough in organic X-ray scintillation technology and is a notable achievement within the X-ray imaging field, paving the way for novel applications in medical imaging and security inspection.

Spectral Photon-Counting Computed Tomography: Technical Principles and Applications in the Assessment of Cardiovascular Diseases.

Spectral Photon-Counting Computed Tomography (SPCCT) represents a groundbreaking advancement in X-ray imaging technology. The core innovation of SPCCT lies in its photon-counting detectors, which can count the exact number of incoming x-ray photons and individually measure their energy. The first part of this review summarizes the key elements of SPCCT technology, such as energy binning, energy weighting, and material decomposition. Its energy-discriminating ability represents the key to the increase in the contrast between different tissues, the elimination of the electronic noise, and the correction of beam-hardening artifacts. Material decomposition provides valuable insights into specific elements' composition, concentration, and distribution. The capability of SPCCT to operate in three or more energy regimes allows for the differentiation of several contrast agents, facilitating quantitative assessments of elements with specific energy thresholds within the diagnostic energy range. The second part of this review provides a brief overview of the applications of SPCCT in the assessment of various cardiovascular disease processes. SPCCT can support the study of myocardial blood perfusion and enable enhanced tissue characterization and the identification of contrast agents, in a manner that was previously unattainable.

The influence of carbon dioxide concentration on carbonation behavior in cement paste

Accelerated carbonation is the main method of simulating carbonation in the laboratory, but there are significant differences in the CO2 concentrations adopted for accelerated carbonation testing among the various standards currently. In this work, X-ray imaging technology was used to study the distribution of the carbonation zone in samples at different CO2 concentrations and used for imaging, which was followed by quantitative analyses of the carbonation profile and the material compositions of the entire carbonation zone in combination with thermogravimetric analysis (TGA) and 29Si nuclear magnetic resonance (29Si NMR) analyses. The results showed that the carbonation profiles of cement paste were similar under 3% and 10% concentration, with the front line of carbonation developing parallel to the soffit of the sample. However, when the concentration was increased to 20%, the carbonation profile at partial carbonation zone could be changed due to shrinkage cracking. In addition, the compositions of the complete carbonation zone under different concentrations were similar, and the development of this zone followed Fick's law.

Development and optimization of a backscatter X-ray detection system based on pencil beam scanning

The backscatter X-ray system makes an image by detecting scattered particles from an object in the opposite direction by Compton scattering. This system has the advantage of detecting drugs or explosives composed of organic substances. In this study, we developed a backscatter X-ray detection system. The 6-ch DAQ system is able to store acquired data for 50 μs as 8 bytes and the 6-ch high voltage power supply board provides adjustable power from 0 to 1600 V. Using this detection system, we varied the tube voltage from 80 to 160 kV and observed backscatter X-ray images of two plastic phantoms at 160 kV. The results indicate a need to optimize the speed of the collimator and data acquisition time of the DAQ system to improve image quality. The backscatter X-ray imaging technology exhibits high scalability, making it applicable not only to security screening but also for medical and industrial purposes.

Bottom-up Gold Filling of Trenches in Curved Wafers

A Bi3+ -stimulated Au electrodeposition process in slightly alkaline Na3AuSO32+Na2SO3 electrolytes has been previously demonstrated for void-free extreme bottom-up filling of high aspect ratio trenches in gratings that are key to advanced X-ray imaging technologies. Effective use of the full area of the gratings with conventional X-ray sources requires they have a finite radius of curvature to align the high aspect ratio Au-filled trenches with divergent X-rays. With that in mind, this work demonstrates bottom-up Au filling in gratings that are attached to curved holders. Contactless mapping of the Au-filled gratings captures residual curvature that is retained after their release from the curved holders (i.e., intrinsic curvature). X-ray diffraction captures the elastic strains in the Si underlying the Au-filled trenches of the grating. Complementary measurements on the surfaces of unpatterned Si wafers mounted on curved holders capture the actual curvatures and strains imposed in the mounted gratings. The gratings, either intrinsically curved or re-bent, provide high visibility across the entire field of view of an X-ray phase contrast imaging system with elastic strains substantially below those in planar gratings bent to the same radius.

White emission metal halides for flexible and transparent x-ray scintillators

Flat-panel x-ray scintillators with a high spatial resolution at a low radiation dose rate are desirable for efficient imaging applications in medical diagnostics, security inspection, and nondestructive inspection. To promote the progress of x-ray imaging technologies, it is of great interest to explore transparent scintillators with reduced light scattering, high light yields, and uniform radioluminescence. Herein, we design and prepare a novel lead-free (C12H28N)2Cu2I4 metal halide featuring a high luminescent efficiency and white emission benefiting from the double self-trapped exciton mechanism, which enable to not only match the response of semiconductor-based sensors but also enhance light yields and decrease exposed doses to objects. Furthermore, transparent, and flexible scintillators with large areas of 20.25 cm2 demonstrate an outstanding scintillation performance including a high spatial resolution of 19.8 lp mm−1 and an ultralow detection limit of 28.39 nGyair s−1, which are ∼4 times higher and 194 times lower than typical values for medical imaging, respectively. This work provides not only a new route to explore promising alternatives with broadband emission but also a novel opportunity to develop flexible x-ray imaging technology.

X-ray free-electron laser induced acoustic microscopy (XFELAM)

The X-ray free-electron laser (XFEL) has remarkably advanced X-ray imaging technology and enabled important scientific achievements. The XFEL’s extremely high power, short pulse width, low emittance, and high coherence make possible such diverse imaging techniques as absorption/emission spectroscopy, diffraction imaging, and scattering imaging. Here, we demonstrate a novel XFEL-based imaging modality that uses the X-ray induced acoustic (XA) effect, which we call X-ray free-electron laser induced acoustic microscopy (XFELAM). Initially, we verified the XA effect by detecting XA signals from various materials, then we validated the experimental results with simulation outcomes. Next, in resolution experiments, we successfully imaged a patterned tungsten target with drilled various-sized circles at a spatial resolution of 7.8 ± 5.1 µm, which is the first micron-scale resolution achieved by XA imaging. Our results suggest that the novel XFELAM can expand the usability of XFEL in various areas of fundamental scientific research.

X-ray image analysis for explosive circuit detection using deep learning algorithms

X-ray imaging technologies find applications across various domains, including medical imaging in health institutions or security in military facilities and public institutions. X-ray images acquired from diverse sources necessitate analysis by either trained human experts or automated systems. In cases where concealed electronic cards potentially pose threats, such as in laptops harboring explosive triggering circuits, conventional analysis methods are challenging to detect, even when scrutinized by skilled. The present investigation is centered on the utilization of deep learning algorithms for the analysis of X-ray images of laptop computers, with the aim of identifying concealed hazardous components. To construct the dataset, some control cards such as Arduino, Raspberry Pi and Bluetooth circuits were hidden inside the 60 distinct laptop computers and were subjected to X-ray imaging, yielding a total of 5094 X-ray images. The primary objective of this study is to distinguish laptops based on the presence or absence of concealed electronic cards. To this end, a suite of deep learning models, including EfficientNet, DenseNet, DarkNet19, DarkNet53, Inception, MobileNet, ResNet18, ResNet50, ResNet101, ShuffleNet and Xception were subjected to training, testing, and comparative evaluation. The performance of these models was assessed utilizing a range of metrics, encompassing accuracy, sensitivity, specificity, precision, f-measure, and g-mean. Among the various models examined, the ShuffleNet model emerged as the top-performing one, yielding superior results in terms of accuracy (0.8355), sensitivity (0.8199), specificity (0.8530), precision (0.8490), f-measure (0.8322), and g-mean (0.8352).

Experimental study on fracture propagation in anisotropy rock under cyclic hydraulic fracturing

Hydraulic fracturing is commonly used to enhance the hydraulic conductivity of geothermal, oil, and gas reservoirs, particularly those situated in enclosed and unconventional formations. Shale oil and gas reservoirs exhibit distinct characteristics in rock mechanics parameters, morphology, natural fracture geometry, and geological features. Structural anisotropy in materials generally arises from changes in grain type and size, weak layering, and variations in layering angles. This study aims to investigate the impact of two key factors, namely cyclic injection and structural anisotropy, on the hydraulic fracturing process. To achieve this goal, the phenomenon of hydraulic fatigue in rock was examined through various cyclic injection methods, and true-triaxial hydraulic fracturing tests were conducted on cubic samples composed of different materials and layers. To evaluate and analyze the fracture morphology of these samples, CT scan X-ray imaging technology was employed. The results revealed that samples subjected to cyclic injection exhibited an average breakdown pressure approximately 30% lower than those subjected to monotonic injection. Fracture geometry in the cyclic injection samples displayed a network pattern with multiple crack branches, while monotonic injection primarily resulted in a single-surface pattern. In samples with differences in horizontal stress, the anisotropy of the sample did not affect the fracture, and the single fracture surface extended in the direction of maximum stress. The energy generated by cyclic injection using the damage-controlled method (cycle duration: 16 s) was concentrated around the borehole, creating a complex fracture network with shorter crack lengths. Conversely, cyclic injection using the ramp signals method (cycle duration: eight seconds) produced more straightforward cracks with greater expansion and penetration. Examination of CT scan images of the fractured samples revealed average tortuosity and fracture volume fraction parameters of 1.117 and 0.027 for cyclic injection, respectively, in contrast to 1.026 and 0.008 for monotonic injection. Furthermore, the S-N damage model based on the results of true-triaxial hydraulic fracturing was introduced to describe rock damage behavior and the concept of fatigue under cyclic loads.

COVID-19 Detection via Ultra-Low-Dose X-ray Images Enabled by Deep Learning.

The detection of Coronavirus disease 2019 (COVID-19) is crucial for controlling the spread of the virus. Current research utilizes X-ray imaging and artificial intelligence for COVID-19 diagnosis. However, conventional X-ray scans expose patients to excessive radiation, rendering repeated examinations impractical. Ultra-low-dose X-ray imaging technology enables rapid and accurate COVID-19 detection with minimal additional radiation exposure. In this retrospective cohort study, ULTRA-X-COVID, a deep neural network specifically designed for automatic detection of COVID-19 infections using ultra-low-dose X-ray images, is presented. The study included a multinational and multicenter dataset consisting of 30,882 X-ray images obtained from approximately 16,600 patients across 51 countries. It is important to note that there was no overlap between the training and test sets. The data analysis was conducted from 1 April 2020 to 1 January 2022. To evaluate the effectiveness of the model, various metrics such as the area under the receiver operating characteristic curve, receiver operating characteristic, accuracy, specificity, and F1 score were utilized. In the test set, the model demonstrated an AUC of 0.968 (95% CI, 0.956-0.983), accuracy of 94.3%, specificity of 88.9%, and F1 score of 99.0%. Notably, the ULTRA-X-COVID model demonstrated a performance comparable to conventional X-ray doses, with a prediction time of only 0.1 s per image. These findings suggest that the ULTRA-X-COVID model can effectively identify COVID-19 cases using ultra-low-dose X-ray scans, providing a novel alternative for COVID-19 detection. Moreover, the model exhibits potential adaptability for diagnoses of various other diseases.

Investigation on the Metal Transfer and Cavity Evolution during Submerged Arc Welding with X-ray Imaging Technology

The physical phenomena of submerged arc welding (SAW) conducted with a 1.6 mm flux-cored wire were investigated using X-ray imaging technique. Three kinds of metal transfer modes were confirmed in this paper, namely the front flux wall-guided droplet transfer, back flux wall-guided droplet transfer, and repelled droplet transfer, of which the corresponding percentages were 47.65%, 45.29%, and 7.06%, respectively. Although the average sizes of the droplets for SAW and FCAW (flux-cored wire welding) were 2.0 mm and 1.9 mm with an average droplet transfer time of 90.3 ms, it required 36.4% more time for the droplet of SAW to finish one metal transfer than it did in FCAW. In addition, the volume of the cavity was not constant but repeated a cycle mode of “expansion and contraction” during the whole process. Thus, the dynamics of the cavity and viscous resistance caused by the flux collectively slowed down the velocity of the droplets from the wire to the weld pool in SAW. Compared with FCAW, a smoother weld without pits and pores was manufactured during the SAW process. Due to the compression effect of the flux, the 14.5 mm average weld width of SAW was 2.9 mm shorter than that of the FCAW. Furthermore, the thickness of slag with a porous structure in SAW was 2.7 times of that in FCAW, indicating that it could provide better protection to the weld of SAW.

Temperature sensitive nanogel-stabilized pickering emulsion of fluoroalkane for ultrasound guiding vascular embolization therapy

Various X-ray imaging technologies like computed tomography (CT) and digital subtraction angiography (DSA) are widely used in transcatheter arterial embolization (TAE) therapy for treating hepatocellular cancer (HCC) patients. Although they display high-contrast imaging, they have a few disadvantages, such as complex operation and exposure to ionizing radiation. Thus, ultrasound (US) imaging plays an important role in medical diagnosis because of its advantages, like simple and fast operation, no ionizing radiation exposure, and accurate real-time imaging. Subsequently, Poly N-isopropylacrylamide-co-2,2,3,4,4,4-Hexafluorobutyl methacrylate (PNF) nanogels were synthesized for stabilizing TGFPE, the Pickering emulsions of 2H, 3H-decafluoropentane (HDFP). These emulsions displayed dual abilities of thermosensitive sol–gel transition and long-term US imaging in vitro. Thus, it was concluded that these emulsions could achieve vascular embolization and long-term US imaging in vivo as per the TAE animal model results. The emulsion droplets’ flow and accumulation were visualized under the US imaging guidance. In summary, the Pickering emulsions have the potential to be used as US-guided embolization material for mediating TAE surgeries.

Application of synchrotron X-ray imaging technology in cellular imaging of nanoprobes

Application of synchrotron X-ray imaging technology in cellular imaging of nanoprobes

Application of advanced light source based X-ray imaging technology in single-cell research

Application of advanced light source based X-ray imaging technology in single-cell research

IMPLEMENTASI INDONESIAN DOSE REFERENCE LEVEL (I-DRL) PADA OPTIMASI FAKTOR EKSPOSI MOBILE X-RAY KAPASITAS 100 MA

. X-ray imaging technology is widely used in medical diagnosis due to its non-invasive nature and ability to provide detailed anatomical images. Diagnostic radiology is the most common practice utilizing X-ray radiation, and the number of examinations has increased substantially over the years. One of the major advancements in this field is the development of mobile X-ray medical devices. The latest mobile X-ray units have a small current capacity of 30 mA – 200 mA, which reduces their weight and makes them more portable. The exposure factor of a mobile X-ray unit is different from that of a stationary one, with higher voltage and lower current strength being used in mobile X-rays. This study aims to determine the correct exposure factor for a 100 mA capacity mobile Air Kerma (INAK) by using a combination of calculation and measurement results obtained through experimental methods. The INAK equation is obtained through suitability test data and is used to calculate INAK and ESAK doses from existing exposure factors. Dose data and image quality were obtained by exposing the attenuation phantom and TOR CDR phantom. The INAK and ESAK results are compared with the INAK and ESAK values on I-DRL. Exposure factor optimization was not carried out as the INAK and ESAK results calculated and measured from the exposure factor table were by I-DRL. The image quality test was carried out visually using a TOR CDR phantom, and a high contrast value of 20.3%, a low contrast value of 0.9%, and a spatial resolution value of 2.5 lp/mm were obtained. In conclusion, the exposure factors used at the Medilab Pekalongan Clinic are optimal and in line with I-DRL. Keywords: I-DRL, Optimization, image quality, mobile X-ray, Entrance Surface Air Kerma (ESAK), Incident Air Kerma (INAK).

Gd3+-sensitized rare earth fluoride scintillators for High-resolution flexible X-ray imaging

X-ray imaging technology is widely used in the medical, industrial, and scientific fields, where highly sensitive, flexible, and cost-effective scintillation screens are crucial prerequisites. In this work, YF3:Gd3+/Tb3+ microparticles (MPs) were prepared via an ultrafast chemical precipitation method and exhibited excellent luminescent properties under the excitation of ultraviolet light and X-ray. It was found that Gd3+ doping could effectively enhance the photoluminescence (PL) and X-ray activated radioluminescence (RL) of Tb3+ owing to an efficient energy transfer process from Gd3+ to Tb3+. The prepared YF3:30%Gd3+/10%Tb3+ MPs exhibited fine environmental stability and superb X-ray RL, which was stronger than that of commercial scintillators Bi4Ge3O12 (BGO) and even comparable to that of CsI:TI single crystal. Highly flexible transparent YF3:Gd3+/Tb3+/PDMS scintillation screens were prepared to record high-resolution X-ray images of planar/nonplanar objects, where the imaging spatial resolution was 16.8 lp mm−1, which was far higher than the standard spatial resolutions required for medical computed tomography (CT) scan (2 lp mm−1) and X-ray imaging (3.5 lp mm−1). The excellent scintillation performance, superior flexibility and environmental stability of YF3:Gd3+/Tb3+/PDMS scintillation films endow them with the potential application in high-resolution industrial nondestructive inspection and biological imaging.

A cadaveric breast cancer tissue phantom for phase-contrast X-ray imaging applications.

As mammography X-ray imaging technologies advance and provide elevated contrast in soft tissues, a need has developed for reliable imaging phantoms for use in system design and component calibration. In advanced imaging modalities such as refraction-based methods, it is critical that developed phantoms capture the biological details seen in clinical precancerous and cancerous cases while minimizing artifacts that may be caused due to phantom production. This work presents the fabrication of a breast tissue imaging phantom from cadaveric breast tissue suitable for use in both transmission and refraction-enhanced imaging systems. Human cancer cell tumors were grown orthotopically in nude athymic mice and implanted into the fixed tissue while maintaining the native tumor/adipose tissue interface. The resulting human-murine tissue hybrid phantom was mounted on a clear acrylic housing for absorption and refraction X-ray imaging. Digital breast tomosynthesis was also performed. Both attenuation-based imaging and refraction-based imaging of the phantom are presented to confirm the suitability of this phantom's use in both imaging modalities.

Control of Liquid Water Transport in Cathode of PEFC Using Wettability-Patterned Electrodes

To address the issue of flooding in polymer electrolyte fuel cells (PEFCs), it becomes imperative to devise an electrode structure capable of actively removing accumulated liquid water within the gas diffusion electrode (GDE). This study aimed to construct a wettability patterned electrode by applying a hydrophilic solution onto the cathode-side gas diffusion layer (GDL). Furthermore, the distribution of liquid water within the patterned electrode during PEFC operation was visualized using X-ray imaging and image processing technology. As a result, it was confirmed that the introduction of a wettability patterned electrode structure enables liquid water transport control during operation and reduces the saturation of liquid water around the hydrophilic region.

High Performance Dynamic X-ray Flexible Imaging Realized Using a Copper Iodide Cluster-Based MOF Microcrystal Scintillator.

X-ray imaging technology has achieved important applications in many fields and has attracted extensive attentions. Dynamic X-ray flexible imaging for the real-time observation of the internal structure of complex materials is the most challenging type of X-ray imaging technology, which requires high-performance X-ray scintillators with high X-ray excited luminescence (XEL) efficiency as well as excellent processibility and stability. Here, a macrocyclic bridging ligand with aggregation-induced emission (AIE) feature was introduced for constructing a copper iodide cluster-based metal-organic framework (MOF) scintillator. This strategy endows the scintillator with high XEL efficiency and excellent chemical stability. Moreover, a regular rod-like microcrystal was prepared through the addition of polyvinyl pyrrolidone during the in situ synthesis process, which further enhanced the XEL and processibility of the scintillator. The microcrystal was used for the preparation of a scintillator screen with excellent flexibility and stability, which can be used for high-performance X-ray imaging in extremely humid environments. Furthermore, dynamic X-ray flexible imaging was realized for the first time. The internal structure of flexible objects was observed in real time with an ultrahigh resolution of 20 LP mm-1 .

Preliminary characterisation of the HEXITECMHz spectroscopic X-ray imaging detector

The HEXITECMHz ASIC is the next generation of the STFC's High Energy X-ray Imaging Technology (HEXITEC). With a ×100 increase in the camera frame rate to 1 MHz, the new ASIC is capable of delivering fully spectroscopic X-ray imaging at photon fluxes of 2×106 photons s-1 mm-2. The improved flux capability ensures the relevance of the technology at a new generation of difraction-limited storage ring (DLSR) synchrotrons as well as enabeling dynamic spectroscopic imaging with sub-keV energy resolution to be carried out on millisecond timescales. In this paper preliminary results from X-ray testing of a 0.3 mm thick p-type Si sensor and 2.0 mm thick HF-CdZnTe sensor at the Diamond Light Source Synchrotron are presented for the first time. Each module consists of 80 × 80 pixels on a 250 μm pixel pitch operated at a temperature of 20°C and a frame rate of 1 MHz. For these preliminary measurements, testing was completed using a prototype test system which limited readout to a portion of the 1 MHz output sampled over an SPI test interface at ∼50 Hz. Despite this limitation these measurements allow the spectroscopic performance of the ASIC to be characterised ahead of the full DAQ system. The prototype detectors were characterised using monochromatic X-rays with energies 12–35 keV at fluxes of (0.6 – 2.5) × 106 photons s-1 mm-2. At an X-ray energy of 12 keV, the energy resolution of the p-type Si and HF-CdZnTe detectors were measured to be 1.0 keV and 1.1 keV respectively. At the higher energies of 20 keV and 35 keV the energy resolution in the HF-CdZnTe was measured to be 1.2 keV and 1.4 keV respectively.