X-ray Imaging Applications Research Articles

Designing LiTaO3:Ln3+,Eu3+ (Ln = Tb or Pr) perovskite dosimeter with excellent charge carrier storage capacity and stability for anti-counterfeiting and flexible X-ray imaging

Designing LiTaO3:Ln3+,Eu3+ (Ln = Tb or Pr) perovskite dosimeter with excellent charge carrier storage capacity and stability for anti-counterfeiting and flexible X-ray imaging

Highly Effective Hybrid Copper(I) Iodide Cluster Emitter with Negative Thermal Quenched Phosphorescence for X-Ray Imaging.

The low efficiency triplet emission of hybrid copper(I) iodide clusters is a critical obstacle to their further practical optoelectronic application. Herein, we present an efficient hybrid copper(I) iodide cluster emitter (DBA)4 Cu4 I4 , where the cooperation of excited state structure reorganization and the metallophilicity interaction enables ultra-bright triplet yellow-orange emission with a photoluminescence quantum yield over 94.9 %, and the phonon-assisted de-trapping process of exciton induces the negative thermal quenching effect at 80-300 K. We also investigate the potential of this emitter for X-ray imaging. The (DBA)4 Cu4 I4 wafer demonstrates a light yield higher than 104 photons MeV-1 and a high spatial resolution of ≈5.0 lp mm-1 , showing great potential in practical X-ray imaging applications. Our new copper(I) iodide cluster emitter can serve as a model for investigating the thermodynamic mechanism of photoluminescence in hybrid copper(I) halide phosphorescence materials.

Scintillation Properties of Lanthanide Doped Pb4Lu3F17 Nanoparticles.

Inorganic scintillators are of great significance in the fields of medical CT, high-energy physics and industrial nondestructive testing. In this work, we confirm that the Pb4Lu3F17: Re (Re = Tb, Eu, Sm, Dy, Ho) crystals are promising candidates for a new kind of scintillator. Detailed crystal structure information is obtained by the Rietveld refinement analysis. Upon X-ray irradiation, all these scintillators exhibited characteristic 4f-4f transitions. The Ce and Gd ions were verified to be useful for enhancing the scintillation intensity via introducing energy transfer processes. The integrated scintillation intensity of the Pb4Lu3F17: Tb/Ce is about 16.8% of the commercial CsI (Tl) single crystal. Our results manifested that Pb4Lu3F17: Re has potential application in X-ray detection and imaging.

A novel multi-view X-ray digital imaging stitching algorithm.

In fan beam X-ray imaging applications, several X-ray images sometimes need to be stitched together into a panoramic image because of the size limitations of the detector. This study aims to propose a novel multi-view X-ray digital imaging stitching algorithm (MVS) based on the CdZnTe photon counting linear array detectors to solve the problem of fan beam X-ray stitching deformation. The panoramic image is generated in four steps including (1) multi-view projection data acquisition, (2) overlapping positioning, (3) weighted fusion and (4) projected pixel value calculation. Images of a globe and foot are scanned by fan beam X-rays and a CdZnTe detector. The proposed method is applied to stitch together the scanned images of the globe. Three other methods are also used for comparison. Finally, this MVS algorithm is also used in the stitching of scanned images of the foot. Compared with the 50% stitching accuracy of other methods, the new MVS algorithm reached a stitching accuracy of 94.4%. Image distortion on the globe and feet is also eliminated and thus image quality is significantly improved. This study proposes a new multi-view X-ray digital imaging stitching algorithm. Study results demonstrate the superiority of this new algorithm and its feasibility in practical applications.

Proposing Intelligent Approach to Predicting Air Kerma within Radiation Beams of Medical X-ray Imaging Systems.

The air kerma is a key parameter in medical diagnostic radiology. Radiologists use the air kerma parameter to evaluate organ doses and any associated patient hazards. The air kerma can be simply described as the deposited kinetic energy once a photon passes through the air, and it represents the intensity of the radiation beam. Due to the heel effect in the X-ray sources of medical imaging systems, the air kerma is not uniform within the X-ray beam's field of view. Additionally, the X-ray tube voltage can also affect this nonuniformity. In this investigation, an intelligent technique based on the radial basis function neural network (RBFNN) is presented to predict the air kerma at every point within the fields of view of the X-ray beams of medical diagnostic imaging systems based on discrete and limited measured data. First, a diagnostic imaging system was modeled with the help of the Monte Carlo N Particle X version (MCNPX) code. It should be noted that a tungsten target and beryllium window with a thickness of 1 mm (no extra filter was applied) were used for modeling the X-ray tube. Second, the air kerma was calculated at various discrete positions within the conical X-ray beam for tube voltages of 40 kV, 60 kV, 80 kV, 100 kV, 120 kV, and 140 kV (this range covers most medical X-ray imaging applications) to provide the adequate dataset for training the network. The X-ray tube voltage and location of each point at which the air kerma was calculated were used as the RBFNN inputs. The calculated air kerma was also assigned as the output. The trained RBFNN model was capable of estimating the air kerma at any random position within the X-ray beam's field of view for X-ray tube voltages within the range of medical diagnostic radiology (20-140 kV).

Highly resolved and refreshable X-ray imaging from Tb3+doped aluminosilicate oxyfluoride glass scintillators

A glass scintillator with high spatial resolution of 20 lp mm−1and refreshable X-ray imaging is designed. The practical tests also reveal the great potential for applications in X-ray imaging.

Application of X-Ray Imaging and Convolutional Neural Networks in the Prediction of Tomato Seed Viability

Tomato fruits are consumed worldwide owing to their health benefits, taste, and flavor. In tomato cultivation, seed viability is directly related to crop productivity. Currently, the methods used to evaluate seed viability involve destructive sampling tests; accordingly, nondestructive methods for predicting seed viability are urgently required. This study aimed to develop X-ray imagery-based models capable of predicting the viability of tomato seeds. Particularly, X-ray-imaged seeds were grown to the seedling stage, and seedlings were classified following their condition. The structural integrity of the seeds was calculated from the X-ray image processing, and an integrity-based viability prediction model was evaluated. Furthermore, convolutional neural network (CNN)-based viability prediction models were developed and evaluated. Both models showed strong performance in distinguishing germinated and non-germinated seeds. However, the CNN-based model revealed greater accuracy in seed viability prediction than the image-processing-based model. The CNN-based model accuracy was 86.01%, with an F1 score of 92.11%, indicating the usefulness of the developed nondestructive testing approach for evaluating tomato seed viability.

Optimization of low-noise read-out electronics for high energy resolution X-ray strip detectors

Semiconductor strip sensors applied as solid-state radiation or particle detectors can be used in radiation detection and measurement for various applications in particle physics experiments, X-ray imaging (e.g. medical), or material science. The X-ray imaging devices with spectroscopic and position resolution features are a very important research topic at many institutes and companies worldwide. Short strip silicon detectors are good candidates for X-ray spectroscopy, because of their relatively small capacitance and leakage current. If additionally, strip pitch is below 100 μm, then the high spatial resolution is also possible. In this paper, the analysis and noise optimization of the read-out electronics for short silicon strip detectors with Charge Sensitive Amplifier (CSA) and shaping amplifier (shaper) is presented. The CSA is optimized for the detector capacitance of around 1.5 pF, and the shaper nominal peaking time is about 1 μs (controlled by the sets of switches). We take into account the sources of noise in a radiation imaging system (current parallel noise, voltage series noise, and 1/f or flicker series noise) both internal (related to the front-end electronics itself) but also external, stemming from a sensor, interconnect, or printed circuit board parasitic components. We target the noise level below 40 el. rms, considering low power consumption (a few mW) and limited channel area.

0D hybrid indium halide as a highly efficient X-ray scintillation and ultra-sensitive fluorescent probe.

Halide perovskite nanocrystal (PNC) of 3D CsPbX3 as a scintillator has aroused intensive attention with advanced applications in radiation detection and X-ray imaging. However, the low light yield and serious toxicity of Pb2+ severely hinder advanced optoelectronic applications. To reduce these fatal shortcomings, a family of new environmentally friendly 0D hybrid lead-free indium halides of [DADPA]InX6·H2O (DADPA = 3,3'-diaminodipropylamine; X = Cl and Br) was prepared. Upon UV excitation, these halides display strong broadband yellow-orange light emissions, and the photoluminescence quantum yield (PLQY) can be optimized up to near unity through the Sb3+-doping strategy. Significantly, high PLQY, negligible self-absorption and low attenuation ability toward X-ray render extraordinary scintillation performance with a high light yield of 51 875 photons MeV-1 and ultralow detection limit of 98.3 nGyair s-1, which is far superior to typical 3D PNC scintillators. Additionally, the ultra-high spatial resolution of 25.15 lp mm-1, negligible afterglow time (2.75 ms) and robust radiant stability demonstrates excellent X-ray imaging performance. To the best of our knowledge, this is the first report on X-ray scintillation based on 0D indium halide materials.

Colloidal KLu3F10:Tb3+ persistent luminescence nanocrystal based flexible detectors for 3D X-ray imaging

Colloidal KLu3F10:Tb3+ persistent luminescence NCs have been synthesized through a simple hydrothermal method, and exhibit excellent flexibility and high sensitivity for X-ray detection and imaging applications.

Enhanced field emission stability of vertically aligned carbon nanotubes through anchoring for X-ray imaging applications

We reported the anchored carbon nanotube emitters shows enhanced field emission stability.

Eu-doped (Y0.85−xLa0.15)2O3sesquioxide transparent ceramics for high-spatial-resolution X-ray imaging

(Y0.85−xLa0.15)2O3:xEu transparent ceramics have good sensitivity, low detection limits and excellent spatial resolution (18.0 lp mm−1), presenting great potential for high-resolution X-ray imaging applications.

Correction: Enhanced field emission stability of vertically aligned carbon nanotubes through anchoring for X-ray imaging applications

Correction for ‘Enhanced field emission stability of vertically aligned carbon nanotubes through anchoring for X-ray imaging applications’ by Xinchuan Liu et al., J. Mater. Chem. C, 2023, 11, 2505–2513, https://doi.org/10.1039/d2tc04363g.

Development of Translucent Ceramics for X-ray Imaging Applications

Development of Translucent Ceramics for X-ray Imaging Applications

Disease Recognition in X-ray Images with Doctor Consultation-Inspired Model.

The application of chest X-ray imaging for early disease screening is attracting interest from the computer vision and deep learning community. To date, various deep learning models have been applied in X-ray image analysis. However, models perform inconsistently depending on the dataset. In this paper, we consider each individual model as a medical doctor. We then propose a doctor consultation-inspired method that fuses multiple models. In particular, we consider both early and late fusion mechanisms for consultation. The early fusion mechanism combines the deep learned features from multiple models, whereas the late fusion method combines the confidence scores of all individual models. Experiments on two X-ray imaging datasets demonstrate the superiority of the proposed method relative to baseline. The experimental results also show that early consultation consistently outperforms the late consultation mechanism in both benchmark datasets. In particular, the early doctor consultation-inspired model outperforms all individual models by a large margin, i.e., 3.03 and 1.86 in terms of accuracy in the UIT COVID-19 and chest X-ray datasets, respectively.

Energy-sensitive scatter estimation and correction for spectral x-ray imaging with photon-counting detectors

As photon counting detectors are being explored for medical and industrial imaging applications, there is a critical need to understand spectral characteristics of scattered x-ray photons. Scattered radiation is detrimental to x-ray imaging by reducing image quality and quantitative accuracy. While various scatter correction techniques have been proposed for x-ray imaging with conventional energy-integrating detectors, additional efforts are required to develop approaches for spectral x-ray imaging with energy-resolving PCDs. We show the benefits of accurate scatter estimation and correction for each energy bin when using a photon counting detector. We propose a scatter estimation model that accounts for the energy-dependent scatter characteristics in projection imaging. This can then be used to restore quantitative accuracy for spectral x-ray imaging with PCDs. Results are shown in the context of contrast-enhanced spectral mammography using dual-energy subtraction to digitally isolate iodine targets (2.5–40 mg/ml). In the presence of scatter, the projected iodine densities are increasingly underestimated as the object thickness increases. The energy-sensitive scatter correction improves the iodine density estimation up to 46%. These results suggest that our scatter estimation model can accurately account for the energy-dependent scatter distribution, which can be an effective tool for scatter compensation in spectral x-ray imaging. Implementing this scatter estimation model does not require any modifications to the acquisition parameters and is transferable to other x-ray imaging applications such as tomosynthesis and CT.

Improved scintillation intensity of CsPbBr3 perovskite film via introducing BaLuF5: Gd/Tb nanoparticles

Metal halide perovskites nanoparticles (PNPs) show promising application in X-ray detection and imaging. However, they exhibit poor stability, especially, the emission peak might be evidently shifted with increasing the PNPs concentration. In this work, the composites of CsPbBr3 PNPs and BaLuF5: 15Gd/15Tb NPs are used to prepare scintillation film for the first time. When fixing the PNPs content in the film, its emission center is not changed after the addition of fluoride NPs. The uniform film containing both BaLuF5: 15Gd/15Tb to CsPbBr3 is prepared. The scintillation intensity of the CsPbBr3 PNPs is enhanced owing to the radiative energy transfer process from BaLuF5: 15Gd/15Tb to CsPbBr3. Our results provide a novel route to improve the scintillation intensity, which might promote the exploration of new scintillators with high performance.

Zero-dimensional rubidium zinc halide blue-emitting quantum dots for X-ray imaging

Low-dimensional-networked metal halide (MH) materials are emerged as a new class of semiconductors owing to their unique structure and outstanding photoelectric properties. Compared with the extensively studied three-dimensional (3D) MHs, the zero-dimensional (0D) MHs are of great interest to be widely studied. Here we report the successful colloidal synthesis of all-inorganic lead-free 0D MHs, including undoped and Cu-doped Rb 2 ZnCl 4 quantum dots (QDs) with bright broad blue and cyan emissions, respectively. Combining the theoretical and experimental study, the band structures are well characterized and the originations of the blue and cyan emissions are attributed to the singlet and triplet self-trapped exciton (STE) emissions, respectively. Finally, owing to the bright radioluminescence (RL), the Cu-doped Rb 2 ZnCl 4 QDs is prepared into a thin film to demonstrate the feasibility for X-ray imaging application. This work not only provides a cyan-emitting all-inorganic 0D MH QDs, but also exploits it as a scintillator for X-ray imaging. • We prepared a novel lead-free all-inorganic 0D metal halide quantum dots (QDs). • Cu-doped Rb 2 ZnCl 4 quantum dots (QDs) show bright broad cyan emission. • The optical properties were studied with the combination of theoretical and experimental study. • Cu-doped Rb 2 ZnCl 4 QDs thin film was prepared to demonstrate the feasibility for X-ray imaging application.

Thermally Activated Delayed Fluorescence Zirconium-Based Perovskites for Large-Area and Ultraflexible X-ray Scintillator Screens.

Flexible scintillator screens with environmental stability, high sensitivity, and low cost have emerged as candidates for X-ray imaging applications. Here, a large-scale and cost-efficient solution synthesis of the vacancy-ordered double perovskite Cs2 ZrCl6 , which is characterized by thermal activation delayed fluorescence (TADF) dominated by triplet emission under X-ray irradiation, is demonstrated. The large Stokes shift and efficient luminescence collection of TADF effectively ensure the light outcoupling efficiency. Further, flexible X-ray scintillator screens with an area of 400 cm2 are prepared using poly(dimethylsiloxane) (PDMS) as the carrier, exhibitingexcellent scintillation properties with light yields as high as 49400 photons MeV-1 , spatial resolutions up to 18 lp mm-1 and detection limits as low as 65 nGy s-1 . Finally, the high-quality imaging results of non-planar and dynamic objects by such screens are demonstrated. It is believed that the explored Cs2 ZrCl6 @PDMS flexible scintillator screens would offer a big step toward expanding the application range of scintillators in different environments.

Semi-automatic method for pre-surgery scoliosis classification on X-ray images using Bending Asymmetry Index.

Bending Asymmetry Index (BAI) has been proposed to characterize the types of scoliotic curve in three-dimensional ultrasound imaging. Scolioscan has demonstrated its validity and reliability in scoliosis assessment with manual assessment-based X-ray imaging. The objective of this study is to investigate the ultrasound-derived BAI method to X-ray imaging of scoliosis, with supplementary information provided for the pre-surgery planning. About 30 pre-surgery scoliosis subjects (9 males and 21 females; Cobb: 50.9 ± 19.7°, range 18°-115°) were investigated retrospectively. Each subject underwent three-posture X-ray scanning supine on a plain mattress on the same day. BAI is an indicator to distinguish structural or non-structural curves through the spine flexibility information obtained from lateral bending spinal profiles. BAI was calculated semi-automatically with manual annotation of vertebral centroids and pelvis level inclination adjustment. BAI classification was validated with the scoliotic curve type and traditional Lenke classification using side-bending Cobb angle measurement (S-Cobb). 82 curves from 30 pre-surgery scoliosis patients were included. The correlation coefficient was R2 = 0.730 (p < 0.05) between BAI and S-Cobb. In terms of scoliotic curve type classification, all curves were correctly classified; out of 30 subjects, 1 case was confirmed as misclassified when applying to Lenke classification earlier, thus has been adjusted. BAI method has demonstrated its inter-modality versatility in X-ray imaging application. The curve type classification and the pre-surgery Lenke classification both indicated promising performances upon the exploratory dataset. A fully-automated of BAI measurement is surely an interesting direction to continue our endeavor. Deep learning on the vertebral-level segmentation should be involved in further study.