High Spatial Resolution Images Research Articles

A 60-channel high-density flexible receive array for pediatric abdominal MRI.

Conventional MRI coils offer suboptimal parallel imaging performance for young children. Our goal was to enhance imaging acceleration by dedicated, flexible high-density coil design for pediatric patients at 3T. We design, construct, and evaluate a highly flexible small loop array. Key design notes include full-wave simulation and analysis of the dual-turn loop, miniature feedboard allocation at the loop center, and cable management. Phantom experiments and adult and pediatric volunteer case studies were conducted to evaluate the small loop array imaging performance compared to commercial reference coils. Dual-turn loop configuration forms higher preamp decoupling impedance than the same size single-turn, supporting a flexible form factor that requires a wide range of critical overlap. Both phantom and in-vivo studies demonstrate superior parallel imaging performance or high spatial resolution imaging using the small loop, compared to commercial reference coils. A dedicated high-density coil array with a minimum inter-component interference layout design allows a flexible form factor and higher imaging accelerations. Phantom and in-vivo volunteer case studies demonstrate promising results in improving efficiency for pediatric patients in routine clinical imaging procedures.

4D Dynamic contrast-enhanced breast CT: Phantom-based reconstruction parameter optimization for iodine quantification.

Four-dimensional dynamic contrast-enhanced breast CT (4D DCE-bCT) offers promising high-resolution spatial and temporal imaging capabilities for the characterization and monitoring of breast tumors. However, the optimal combination of parameters for iodine quantification in image space remains to bedetermined. This study aims to optimize a dedicated bCT system to perform long dynamic contrast-enhanced scans with high spatio-temporal resolution while maintaining a reasonable radiation dose. Our protocol includes the acquisition of a high-quality prior image that is reconstructed with a polychromatic iterative algorithm (IMPACT). The acquisition of the post-contrast sequence is continuous but sparse and these images are reconstructed using prior image constrained compressed sensing (PICCS). A four-step optimization process is performed using images of a physical phantom. First, the optimal tube current is selected by taking the noise level into account. Second, the optimal number of angles is selected based on the absence of streak artifacts. Third, the number of iterations in IMPACT is specified at the lowest value that achieves the highest spatial resolution. Finally, the number of iterations in PICCS is determined based on the quantitative accuracy of a range of iodine concentrations. When a high-quality prior image is available, the imaging of post-contrast images can be performed using just 40 projection angles with a tube current of 32 mA. The noise level in the post-contrast images is inherited from the prior image and no streak artifacts are visible. Mean difference between the linear attenuation coefficients of samples containing iodine reconstructed with IMPACT using all 360 projections and PICCS using 40 projections is 0.0004 at most. The spatial resolution of images reconstructed with PICCS is lower than the one of IMPACT images and is concentration dependent. The cut-off frequency at 10% modulation transfer function drops from 1.55 in the prior image to 0.9 when the target with the largest concentration is evaluated. The total mean glandular dose of the protocol does not exceed 22.5mGy. This study found the optimal acquisition and reconstruction parameters for a low-dose dynamic contrast-enhanced bCT protocol. The numerical accuracy of the proposed protocol was ensured by performing a physical phantomstudy.

Efficient and Robust Europium(III)‐Based Hybrid Lanthanide Scintillators for Advanced X‐Ray Imaging

AbstractScintillators that convert ionizing radiation into low‐energy photons are essential for medical diagnostics and industrial inspections. Despite advances in X‐ray scintillators, challenges remain in achieving high efficiency, environmental compatibility, stability, and flexibility. Here, we present experimental investigations of a new type of europium(III)‐based hybrid ternary complex scintillators for improved X‐ray detection and imaging. Benefiting from the synergistic interaction between dual organic ligands and lanthanide ions, the Eu(TTA)3Phen complex demonstrates exceptional radioluminescence and light yield under X‐ray excitation, with a detection limit of 19.97 nGy s−1, well below typical radiation doses used in medical diagnostics. Moreover, lanthanide complex Eu(TTA)3Phen exhibited excellent thermal and photostability, showing minimal degradation even after extended X‐ray exposure. By integrating with flexible polymer matrices, a high‐transmission Eu(TTA)3Phen‐PMMA composite film was fabricated for X‐ray radiography, demonstrating high spatial resolution (<10 um) and superior image quality across various target samples. These findings hold substantial promise for next‐generation X‐ray imaging applications, offering high sensitivity, stability, flexibility, and versatility, making them ideally suited for advanced radiographic systems.

Efficient and Robust Europium(III)-Based Hybrid Lanthanide Scintillators for Advanced X-Ray Imaging.

Scintillators that convert ionizing radiation into low-energy photons are essential for medical diagnostics and industrial inspections. Despite advances in X-ray scintillators, challenges remain in achieving high efficiency, environmental compatibility, stability, and flexibility. Here, we present experimental investigations of a new type of europium(III)-based hybrid ternary complex scintillators for improved X-ray detection and imaging. Benefiting from the synergistic interaction between dual organic ligands and lanthanide ions, the Eu(TTA)3Phen complex demonstrates exceptional radioluminescence and light yield under X-ray excitation, with a detection limit of 19.97 nGy s-1, well below typical radiation doses used in medical diagnostics. Moreover, lanthanide complex Eu(TTA)3Phen exhibited excellent thermal and photostability, showing minimal degradation even after extended X-ray exposure. By integrating with flexible polymer matrices, a high-transmission Eu(TTA)3Phen-PMMA composite film was fabricated for X-ray radiography, demonstrating high spatial resolution (<10 um) and superior image quality across various target samples. These findings hold substantial promise for next-generation X-ray imaging applications, offering high sensitivity, stability, flexibility, and versatility, making them ideally suited for advanced radiographic systems.

Preliminary study on the correlation between thyroid magnetic resonance parameters and radiation dose after radiotherapy for nasopharyngeal carcinoma.

Hypothyroidism is a common sequela after radiotherapy for nasopharyngeal carcinoma (NPC). Magnetic resonance imaging (MRI) has gained prominence in thyroid imaging, leveraging its non-ionizing radiation, high spatial resolution, multiparameter and multidirectional imaging. Few previous studies have investigated the evaluation of radiation-induced thyroid injury by MRI. MRI and radiotherapy data of 32 patients who were first diagnosed with nasopharyngeal carcinoma in our hospital from April 2015 to April 2024 and underwent radiotherapy in the radiotherapy department were retrospectively collected. Before, during and after radiotherapy, the thyroid morphology was observed on MR images, and the quantitative parameters of size (width, thickness) were measured on T1-weighted images. The signal intensity (SI) of the thyroid gland was measured on T1-weighted imaging (T1WI), T2-weighted imaging (T2WI) and contrast-enhanced T1-weighted imaging. The differences in thyroid parameters at different time points before and after radiotherapy were compared. The correlation between the MRI quantitative parameters of the thyroid and the radiation dose volume of the thyroid and the radiation dose of the pituitary were analyzed. The width, thickness and volume of the thyroid decreased gradually before, during and 6 and 12 months after radiotherapy. They were negatively correlated with the mean thyroid dose and V50 (p < 0.05), but were not significantly correlated with the maximum and minimum thyroid doses, V30 and V35 (p > 0.05). The T1WI relative signal intensity (RSI), T2WI RSI, and enhanced T1WI RSI of the thyroid gland gradually decreased from before radiotherapy to during radiotherapy and 6 months and 12 months after radiotherapy. The T1WI RSI, T2WI RSI, and enhanced T1WI RSI during radiotherapy and 6 months and 12 months after radiotherapy were negatively correlated with the mean radiation dose, V40, V45, and V50 of the thyroid gland (p < 0.05), but were not significantly correlated with the maximum radiation dose, minimum radiation dose, V30, and V35 of the thyroid gland or the radiation dose of the pituitary gland (p > 0.05). Quantitative MRI analysis can non-invasively and effectively show the changes in thyroid shape, size and signal intensity in patients with nasopharyngeal carcinoma before and after radiotherapy, which is crucial for early and accurate assessment of thyroid damage, enabling timely treatment to preserve thyroid function.

Assessing the dosimetric effects of high-Z titanium implants in proton therapy using pixel detectors

A rapid increase in the use of proton therapy for cancer treatment has been seen in the last decade due to its clinical advantages. Therefore, more and more patients with implants and other metallic devices will be among those who will be treated. This study experimentally examines the effect and changes in the delivered fields, using water-equivalent phantoms with and without titanium (Ti) dental implants positioned along the primary beam path. We measured in detail the composition and spectral-tracking characterization of particles generated in the plateau region of the Bragg curve towards the Sub-peak region using high-spatial resolution, spectral and time-sensitive imaging detectors with a pixelated array provided by the ASIC chip Timepix3. A 170 MeV proton beam was collimated and modulated in a polymethyl methacrylate (PMMA) block. Placing two dental implants behind the PMMA block, the radiation was measured using two pixeled detectors with silicon (Si) sensors. The Timepix3 (TPX3) detectors measured in detail particle fluxes, dose rates (DR) and linear energy transfer (LET) spectra for resolved particle types. Artificial intelligence (AI) based-trained neural networks (NN) calibrated in well-defined radiation fields were used to analyze and identify particles based on morphology and characteristic spectral-tracking response. The beam was characterized and single-particle tracks were registered and decomposed into particle-type groups. The resulting particle fluxes in both setups are resolved into three main classes of particles: i) protons, ii) electrons and photons, and iii) ions. Protons are the main particle component responsible for dose deposition. High-energy transfer particles (HETP), namely ions exhibited differences in both dosimetric aspects that were investigated: DR and particle fluxes, when the Ti implants were placed in the setup. The detailed multi-parametric information of the secondary radiation field provides a comprehensive understanding of the impact of Ti materials in proton therapy.

Characterization of seven transiting systems, including four warm Jupiters from SOPHIE and TESS

While several thousand exoplanets are now confirmed, the number of known transiting warm Jupiters ($10 d period d $) remains relatively small. These planets are generally believed to have formed outside the snowline and migrated to their current orbits. Because they are sufficiently distant from their host stars, they mitigate proximity effects and so offer valuable insights into planet formation and evolution. Here, we present the study of seven systems, three of which -- TOI-2295, TOI-2537, and TOI-5110 -- are newly discovered planetary systems. Through the analysis of TESS photometry, SOPHIE radial velocities (RVs), and high-spatial resolution imaging, we found that TOI-2295b, TOI-2537b, and TOI-5110b are transiting warm Jupiters with orbital periods ranging from 30 to 94 d, masses between 0.9 and 2.9 M_ J and radii ranging from 1.0 to 1.5 R_ J . Both TOI-2295 and TOI-2537 harbor at least one additional, outer planet. Their outer planets -- TOI-2295c and TOI-2537c -- are characterized by orbital periods of 966.5^ and 1920^ d, respectively, and minimum masses of 5.61^ and 7.23^ M_ J respectively. We have also investigated and characterized the two recently reported warm Jupiters TOI-1836b and TOI-5076b, which we independently detected in SOPHIE RVs. Our new data allow for further discussion of their nature and refinement of their parameters. Additionally, we study the planetary candidates TOI-4081.01 and TOI-4168.01. For TOI-4081.01, despite our detection in RVs, we cannot rule out perturbation by a blended eclipsing binary, and we thus exercise caution regarding its planetary nature. On the other hand, we identify TOI-4168.01 as a firm false positive; its RV curve exhibits a large amplitude in an antiphase relation with the transit ephemeris observed by TESS, indicating that the detected event is the eclipse of a secondary star rather than a planetary transit. Finally, we highlight interesting characteristics of these new planetary systems. The transits of TOI-2295b are highly grazing, with an impact parameter of 1.056^ . This leaves its radius uncertain but potentially makes it an interesting probe of gravitational dynamics in its two-planet system, as transit shapes for grazing planets are highly sensitive to even small variations in inclination. TOI-2537b, in turn, is a temperate Jupiter with an effective temperature of 307±15 K and can serve as a valuable low-irradiation control for models of hot Jupiter inflation anomalies. We also detected significant transit timing variations (TTVs) for TOI-2537b, which are likely caused by gravitational interactions with the outer planet TOI-2537c. Further transit observations are needed to refine the analysis of these TTVs and enhance our understanding of the system’s dynamics. Finally, TOI-5110b stands out due to its orbital eccentricity of 0.745^ one of the highest planetary eccentricities discovered thus far. We find no conclusive evidence for an external companion, but an unseen planet with a semi-amplitude smaller than 10 m/s could nonetheless still be exciting its eccentricity.

Synergic sensing of light and heat emitted by offshore oil and gas platforms in the South China Sea

ABSTRACT Facing the growing global demand for oil resources and the industry’s commitment to decarbonization, there is a need for customized monitoring of oil and gas (OG) platforms. Remote sensing has proved an effective approach for OG platform observation compared to in-situ surveys. However, coarse spatial resolution and unbefitting spectra confine the application in monitoring platform activities. The Sustainable Development Science Satellite 1 (SDGSAT-1) has a comprehensive advantage, providing high spatial resolution (up to 10 m) and wide swath (300 km) imaging capability while enabling synchronous observation of the Glimmer Imager (GLI) and Thermal Infrared Spectrometer (TIS) at night. In this study, we demonstrated for the first time the synergic application of the SDGSAT-1 GLI and TIS to observe offshore OG platforms, probing their peculiar activities of associated gas flaring. By incorporating GLI visible colour bands, we developed an algorithm for gas flaring detection, pinpointing 113 active OG platforms in the South China Sea. The SDGSAT-1 not only pinpoints the offshore OG platforms but also provides insights into understanding their light- and heat-emitting variations. These findings highlight the competence of SDGSAT-1 in tracking the operational status of OG platforms and contributing to further refining the OG platform inventory.

In Vivo Contactless, Cellular-Resolution Imaging of the Healthy and Pathological Human Limbus With 250-kHz Point-Scanning SD-OCT.

To demonstrate that high-seed, ultra-high-resolution spectral-domain optical coherence tomography (SD-OCT) technology can image in vivo fine morphological features in the healthy and pathological human limbus. A compact, fiberoptic SD-OCT system was developed for imaging the human limbus. It combines ∼1.5-µm isotropic spatial resolution in ocular tissue and an acquisition rate of 250,000 A-scans per second. The imaging probe was outfitted with two microscope objectives to provide flexibility in the choice of wide field of view and extended depth of focus versus high lateral resolution. The clinical potential of the system was evaluated by imaging subjects with limbal stem cell dysfunction (LSCD; n = 4) and healthy controls (n = 6). Limbus images acquired from the healthy controls showed normal cellular structure of the limbal crypts, palisades of Vogt (POVs), and vasculature of the underlying scleral tissue. Images acquired from the LSCD subjects showed distortions or absence of POVs, invasion of highly scattering conjunctival tissue over the limbal and peripheral corneal epithelium, scarring and thinning of the limbal epithelium, and neovascularization. The combination of high OCT spatial resolution and rapid image acquisition rate allows for in vivo, contactless, volumetric visualization of fine morphological details that could be beneficial for the precise diagnosis and grading of LSCD, planning of treatment, and evaluation of the effectiveness of the treatment approaches. The OCT technology described here could improve the clinical diagnostics and grading of LSCD, preoperative planning, and postoperative evaluation of LSCD subjects, in addition to monitoring the effectiveness of various LSCD treatments.

Detectability and cortical depth dependence of stimulus-driven high-frequency BOLD oscillations in the human primary somatosensory and motor cortex

Abstract In functional magnetic resonance imaging (fMRI), neural activity is inferred from the associated hemodynamic response. However, the degree to which hemodynamics can track dynamic changes in neuronal activity, and thus the ultimate temporal resolution of fMRI, remains unknown. To evaluate the detectability of stimulus-driven high-frequency blood oxygenation level dependent (BOLD) signal oscillations in functionally and vascularly distinct cerebral cortical areas, stimuli up to 0.5 Hz were used to evoke activation in the primary somatosensory and motor cortex. Despite their functional and vascular differences, a similar frequency dependence was observed in both cortical areas. We then proceeded to investigate these signals at different levels of the cortical vascular hierarchy, using cortical depth as a proxy. We observed that, above 0.33 Hz, the BOLD response amplitude decreased faster with increasing frequency near the pial surface than in the parenchyma, suggesting that, in addition to exhibiting high spatial specificity, parenchymal signals—accessible with high spatial resolution imaging—also attenuate less rapidly when the stimulus frequency is increased. In addition, as the stimulus frequency increased, we observed larger relative phase differences in the BOLD oscillations across cortical depths. When averaged across depths, these signals can thus interfere destructively, suggesting that high spatial resolutions can avoid this phase cancellation and thereby aid in the detection of rapid BOLD oscillations.

Galaxy morphologies revealed with Subaru HSC and super-resolution techniques. II. Environmental dependence of galaxy mergers at z ∼ 2–5

Abstract We super-resolve the seeing-limited Subaru Hyper Suprime-Cam (HSC) images for 32187 galaxies at $z\sim 2$–5 using three techniques, namely, the classical Richardson–Lucy (RL) point spread function (PSF) deconvolution, sparse modeling, and generative adversarial networks, to investigate the environmental dependence of galaxy mergers. These three techniques generate overall similar high spatial resolution images but with some slight differences in galaxy structures; for example, more residual noises are seen in the classical RL PSF deconvolution. To alleviate the disadvantages of each technique, we create combined images by averaging over the three types of super-resolution images, resulting in galaxy substructures resembling those seen in the Hubble Space Telescope images. Using the combined super-resolution images, we measure the relative galaxy major merger fraction corrected for the chance projection effect, $f_{\rm merger}^{\rm rel,col}$, for galaxies in the $\sim$300 deg$^2$ area data of the HSC Strategic Survey Program and the CFHT Large Area U-band Survey. Our $f_{\rm merger}^{\rm rel,col}$ measurements at $z\sim 3$ validate previous findings showing that $f_{\rm merger}^{\rm rel,col}$ is higher in regions with a higher galaxy overdensity $\delta$ at $z\sim 2$–3. Thanks to the large galaxy sample, we identify a nearly linear increase in $f_{\rm merger}^{\rm rel,col}$ with increasing $\delta$ at $z\sim 4$–5, providing the highest-z observational evidence that galaxy mergers are related to $\delta$. In addition to our $f_{\rm merger}^{\rm rel,col}$ measurements, we find that the galaxy merger fractions in the literature also broadly align with the linear $f_{\rm merger}^{\rm rel,col}$–$\delta$ relation across a wide redshift range of $z\sim 2$–5. This alignment suggests that the linear $f_{\rm merger}^{\rm rel,col}$–$\delta$ relation can serve as a valuable tool for quantitatively estimating the contributions of galaxy mergers to various environmental dependences. This super-resolution analysis can be readily applied to datasets from wide field-of-view space telescopes such as Euclid and Roman.

Quantitative elemental sensitive imaging based on K-edge subtraction tomography

Background K-edge subtraction (KES) tomography has been extensively utilized in the field of elemental sensitive imaging due to its high spatial resolution, rapid acquisition, and three-dimensional (3D) imaging capabilities. However, previous studies have primarily focused on the qualitative analysis of element contents, rather than quantitative assessment. Objective The current study proposes a novel method for quantitative elemental analysis based on K-edge subtraction tomography. Methods The linear correlation between the slice grayscale of standard samples and the difference in their linear absorption coefficients is confirmed. This finding suggests that the grayscale data from slices may be employed to perform quantitative estimations of elemental compositions. Results In order to verify the accuracy and validity of this method, the target element contents in standard and actual samples are quantitatively analyzed, respectively. The results demonstrate that the method is capable of achieving nanometer-resolved quantitative elemental sensitive imaging with a relative error of less than 3% in the target elemental content. Conclusions The method described in this paper is expected to expand the scope of applications for K-edge subtraction tomography and provide a novel approach to achieve more precise and convenient quantitative elemental analysis.

Operando Bragg Coherent Diffraction Imaging of Commercial Polycrystalline and Single Crystal NMC811 Electrodes

Commercial candidates for electric vehicle batteries include Ni-rich Li(Ni0.8Mn0.1Co0.1)O2 (NMC811) cathodes due to their high specific capacity (200 mAh/g) and reduced cobalt content, which has positive socio-economic repercussions. Despite all of the advantages, these materials suffer from a range of degradation modes, many of which are associated with the redox and crystallographic behavior at high states of charge and are thought to be the cause of rapid capacity fade. NMC811 suffers from anisotropic changes in the crystal structure during cycling, which induce strain and can then lead to issues such as particle crack formation. Gathering data at multiple length scales is imperative for understanding the discrete mechanisms at play. Bragg Coherent Diffraction Imaging (BCDI) is a key tool for obtaining data at the nano-scale by providing high spatial resolution images of individual particles. BCDI also affords the unique opportunity to resolve the strain of individual crystals at the picometer scale, producing data with the highest quantifiable imaging resolution of battery electrodes and allowing for the detection of evolving defect modes such as shearing and stacking faults in the crystals during cycling.NMC811 typically employs the archetypal cathode particle morphology, consisting of a secondary particle agglomerate (~ 10 μm) made up of nanometer-sized primary particles. It is widely accepted that crack formation occurs at grain boundaries between primary particles. One mitigation method is to switch to a single crystal morphology, reducing the number of grain boundaries within particles and therefore improving overall performance. However, there is still a limited understanding of the subtle mechanistic differences between the two morphologies during cycling.In this work, Operando BCDI was employed to study both polycrystalline and single crystal NMC811 electrodes in both pristine and aged states. Non-uniform distributions of inter- and intracrystal strain were observed for both polycrystalline and single crystal morphologies, even in the pristine state. Strain values an order of magnitude higher were observed for polycrystalline NMC811 compared to single crystal NMC811, likely a cause for the single crystal morphology’s superior performance. The nucleation of crystal splitting was also observed for a pristine single crystal during cycling, which could subsequently result in intergranular cracking. This feature is only resolvable with extremely high-resolution techniques such as BCDI. This work ultimately adds to the understanding of the central role of crystal-scale dynamics during cycling and the potential ramifications for a cell's electrochemical performance, leading to informed material design.

Single-cell resolution spatial analysis of antigen-presenting cancer-associated fibroblast niches.

Recent studies have identified a unique subtype of cancer-associated fibroblasts (CAFs) termed antigen-presenting CAFs (apCAFs), which remain the least understood CAF subtype. To gain a comprehensive understanding of the origin and function apCAFs, we construct a fibroblast molecular atlas across 14 types of solid tumors. Our integration study unexpectedly reveals two distinct apCAF lineages present in most cancer types: one associated with mesothelial-like cells and the other with fibrocytes. Using a high-resolution single-cell spatial imaging platform, we characterize the spatial niches of these apCAF lineages. We find that mesothelial-like apCAFs are located near cancer cells, while fibrocyte-like apCAFs are associated with tertiary lymphoid structures. Additionally, we discover that both apCAF lineages can up-regulate the secreted protein SPP1, which facilitates primary tumor formation and peritoneal metastasis. Taken together, this study offers an unprecedented resolution in analyzing apCAF lineages and their spatial niches.

Fast and universal single-molecule localization using multi-dimensional point spread functions

The recent development of single-molecule imaging techniques has enabled not only high accuracy spatial resolution imaging but also information rich functional imaging. Abundant information about single molecules can be encoded in its diffraction pattern and be extracted precisely (e.g. 3D position, wavelength, dipole orientation). However, sophisticated high dimensional point spread function (PSF) modeling and analyzing methods have greatly impeded the broad accessibility of these techniques. Here, we present a graphics processing unit (GPU) -based B-spline PSF modeling method that could flexibly model high dimensional PSFs with arbitrary shape without greatly increasing the model parameters. Our B-spline fitter achieves 100 times speed improvement and minimal uncertainty for each dimension, enabling efficient high dimensional single-molecule analysis. We demonstrated, both in simulations and experiments, the universality and flexibility of our B-spline fitter to accurately extract the abundant information from different types of high dimensional single-molecule data, including multicolor PSF (3D + color), multi-channel four-dimensional 4Pi-PSF (3D + interference phase) and five-dimensional vortex PSF (3D + dipole orientation).

Zonal and Regional Jupiter Brightness Trends from the Hubble Outer Planet Atmospheres Legacy Program

The Hubble Outer Planet Atmospheres Legacy program began in 2014 and has observed Jupiter yearly from 2015 to 2024. Using high spatial resolution imaging from the Hubble Wide Field Camera 3, brightness trends were investigated focusing on the unique UV capability and absolute calibration consistency of the Hubble Space Telescope. From these data, a 4–5 yr period is observed at 24° north, particularly in the blue (F395N) and methane gas absorption (FQ889N) filters. Additionally, several wavelengths show a potential seasonal periodicity, especially at the equator, but more years of data are needed to confirm this trend over multiple Jupiter years. Variability in Oval BA and the Great Red Spot brightness is not cyclical, but these two anticyclonic features show changes on a yearly timescale.

Satellite-Based Coral Reef Habitat Mapping in Weno Island Using Water Column Corrected High Spatial Resolution Image

Satellite-Based Coral Reef Habitat Mapping in Weno Island Using Water Column Corrected High Spatial Resolution Image

Reference-based image super-resolution of hyperspectral and red-green-blue image for determination of wheat kernel quality using deep learning networks

In the process of cultivation and harvest, wheat kernel quality is highly susceptible to various factors, such as disease, mildew, atrophy and impurities, and detection of kernel quality is essential to avoid hazard proliferation, facilitate product grading, and ensure food safety. Possessing abundant image and spectral characteristics, hyperspectral imaging (HSI) has gained impressive achievements in kernel quality analysis, but its low spatial resolution limits its detection accuracy. In this study, reference-based image super-resolution (RefSR) of HSI and Red-Green-Blue image was adopted to improve resolution to determine wheat kernel quality using deep learning networks. Firstly, RefSR was conducted by the improved transformer network with dual-branch feature extraction and weighted fusion operation and achieved excellent RefSR with significant resolution improvement, peak signal to noise ratio of 35.521 and structural similarity index of 0.97, outweighing the existing state-of-the-art networks. Then, the reflectance images (RIs) of effective wavelengths (EWs) from generated HSI images were combined with the residual network with a spatial, channel attention and multi-scale residual to determine wheat kernel quality. Precise analysis was achieved with the accuracy in calibration, validation and prediction sets of 100.00%, 95.26% and 92.78%. RefSR provides a novel and efficient approach for obtaining HSI images of high spatial resolution and facilitates the application of HSI in analysis of crop kernels. RIs of several sporadic EWs can be easily acquired and processed, achieving field and rapid kernel detection. Therefore, the proposed method furnishes the efficient, accurate and applicable determination of wheat kernel quality.

Feasibility of thin-slice, low noise images created using multi-kernel synthesis to replace multiple image series in head CT.

SynthesiZed Improved Resolution and Concurrent nOise reductioN (ZIRCON) is a multi-kernel synthesis method that creates a single series of thin-slice computed tomography (CT) images displaying low noise and high spatial resolution, increasing reader efficiency and minimizing partial volume averaging. To compare the diagnostic performance of a single set of ZIRCON images to two routine clinical image series using conventional CT head and bone reconstruction kernels for diagnosing intracranial findings and fractures in patients with trauma or suspected acute neurologic deficit. In total, 50 patients underwent clinically indicated head CT in the ER (15 normal, 35 abnormal cases). A non-reader neuroradiologist established the reference standard. Three neuroradiologists reviewed two routine clinical series (head and bone kernels) and a single ZIRCON series, detecting intracranial findings or fractures and rating confidence (0-100). Sensitivity, specificity, and jackknife free-response receiver operating characteristic (JAFROC) figure of merit (FOM) were compared (limit of non-inferiority: -0.10). ZIRCON and conventional images demonstrated comparable performance for fractures (sensitivity: 51.5% vs. 54.5%; specificity: 40.2% vs. 34.2%) and intracranial findings (sensitivity: 88.2% vs. 91.4%; specificity: 77.2% vs. 73.7%).The estimated difference of JAFROC FOM demonstrated ZIRCON non-inferiority for acute pathologies overall (0.003 [95% CI=-0.051-0.057]) and fractures (0.048 [95% CI=-0.050-0.145]) but not for intracranial findings alone (-0.024 [95% CI=-0.100-0.052]). Thin-slice, low noise, and high spatial resolution images can be created to display intracranial findings and fractures replacing multiple images series in head CT with similar performance. Future studies in more patients and further algorithmic development are warranted.

Fast On-Site Speciation and High Spatial Resolution Imaging of Labile Arsenic in Freshwater and Sediment Using the DGT-SERS Sensor.

Diffusive gradients in thin films (DGT) technique is renowned for in situ passive sampling but not for rapid on-site analysis, whereas surface-enhanced Raman spectroscopy (SERS) excels in ultrasensitive on-site detection but is limited by substrate contamination from complex matrices. Here, a hierarchical nanostructure of silver (Ag) mirror-supported large Ag nanoparticles (∼120 nm) was grown in situ in polyacrylamide hydrogel with a restricted pore size (PAM/Ag mirror/AgNPs) to serve as both the DGT binding phase and the SERS substrate. The substrate exhibited a maximum electric field enhancement factor of 9.9 × 108 and a signal relative standard error of 4.8%. Using the DGT-SERS sensor, As(III) and As(V) in freshwater were simultaneously detected at limits of 0.9 and 0.8 μg L-1, respectively, applicable across a wide range of environmental conditions. The DGT-SERS effectively mitigated the interfacial reduction of As(V) caused by humic acid by excluding it from plasmonic hotspots through size exclusion of the diffusive layer. The Raman analysis of a DGT sample in the field requires only 2 s using a portable spectrometer without DGT device disassembly. More importantly, the DGT-SERS captured the first two-dimensional image of As(III) and As(V) in one DGT at the micron scale resolution, revealing their spatially supplementary distribution patterns at the sediment-water interface. This study paves the way for next-generation speciation imaging DGT and the application of SERS in complex environments.