High-resolution Imaging Research Articles

Neuroanatomical correlates of subjective tinnitus: insights from advanced cortical morphology analysis.

Subjective tinnitus, characterized by the perception of phantom sounds in the absence of external stimuli, presents significant challenges in both audiology and neurology. Once thought to primarily involve aberrant neural activity within auditory pathways, it is now understood to engage a broader array of neuroanatomical structures. This study investigated the connections between auditory, cognitive, and sensory processing regions, which are crucial for unraveling the complex neurobiological basis of tinnitus. Using high-resolution T1-weighted magnetic resonance imaging, we compared 52 individuals with subjective tinnitus with 52 age-matched healthy controls, focusing on cerebral cortex features, including fractal dimensionality, gyrification, and sulcal depth. Covariate analyses were conducted to explore the relationships between tinnitus duration, Tinnitus Handicap Inventory scores, anxiety score, and neuroanatomical changes. We found significant alterations in key brain regions involved in sensory processing, cognition, and emotional regulation, including the insula, lateral occipital cortex, middle frontal gyrus, and superior parietal lobule. These neuroanatomical changes were strongly correlated with the severity and chronicity of tinnitus symptoms. Our findings reveal profound structural changes in the brain associated with subjective tinnitus, offering valuable insights into the condition's underlying mechanisms and providing a potential framework for guiding future research and therapeutic interventions.

Spondylodiscitis of the thoraco-lumbar spine: diagnostic performance of dual-energy CT vs MRI.

Dual-energy computed tomography (DECT) could combine the high-resolution bone window images made available by multi-detector CT technology with its capability to identify bone marrow edema (BME) in the spine, for diagnosing spondylodiscitis. Our objective was to compare the diagnostic performance of contrast-enhanced MRI and non-contrast DECT to identify spondylodiscitis of the thoraco-lumbar spine. This prospective study included 77 consecutive participants (39 males; mean age of 61) who underwent DECT and MRI (within 7 days) between January 2020 and October 2023. DECT data were post-processed on a dedicated offline workstation (SyngoVia® VB20) by using a three-material decomposition algorithm. Four radiologists, blinded to clinical data, evaluated non-contrast DECT and contrast-enhanced MRI images. The diagnosis of spondylodiscitis was based on vertebral edema, disc edema, endplate erosions, and paraspinal involvement. Diagnostic accuracy values were calculated by using biopsy as a standard of reference. A multi-reader multi-case analysis was performed. Biopsy revealed a diagnosis of spondylodiscitis in 46 patients (60%). Thoracic and lumbar spondylodiscitis were diagnosed in 37/46 (80%) and 9/46 (20%) patients, respectively. DECT and MRI overall sensitivity, specificity, and AUC were 0.91, 0.89, and 0.90, and 0.94, 0.93, and 0.93, respectively. At lumbar and thoracic levels, the difference between AUC values between DECT and MRI was not significant (p = 0.15). For DECT and MRI, a very good inter-reader agreement was achieved (k = 0.90 and k = 0.97, respectively). Contrast-enhanced MRI represents the most accurate imaging tool for the diagnosis of spondylodiscitis. However, only a non-significant drop in diagnostic performance was achieved by evaluating non-contrast DECT images. Question To compare the diagnostic performance of contrast-enhanced MRI and non-contrast DECT for identifying spondylodiscitis of the thoraco-lumbar spine. Findings MRI was not significantly superior compared to DECT in diagnosing spondylodiscitis, whereas the inter-reader agreement was near perfect for both MRI and DECT. Clinical relevance DECT represents a fast and accurate imaging tool for the demonstration of BME, erosions, and peri-vertebral inflammation in thoraco-lumbar spondylodiscitis.

Utilizing collagen-coated hydrogels with defined stiffness as calibration standards for AFM experiments on soft biological materials: the case of lung cells and tissue

Abstract Atomic Force Microscopy (AFM) is crucial in mechanobiology for high-resolution imaging and nanomechanical measurements of biological samples, providing insights into their mechanical properties. However, AFM faces challenges such as tip damage and cantilever selection errors, impacting measurement accuracy. This study proposes a methodology using collagen-coated hydrogels with predefined stiffness for calibrating AFM measurements on soft biological materials. By facilitating appropriate cantilever selection, assessing systematic errors, and evaluating tip damage, this approach ensures reliable Young’s modulus measurements. The proof of concept with human lung cells and tissue specimens demonstrates improved accuracy and reliability of AFM-based nanomechanical characterizations, essential for understanding cellular mechanics and disease progression.

Neck lumps: Early Detection with Dental Magnetic Resonance Imaging?

Cervical lymphadenopathy can indicate a range of diseases, including infections, inflammation, and neoplastic processes. Accurate diagnosis is crucial for identifying the underlying cause and determining appropriate treatment. Diagnostic procedures include clinical examination, ultrasound, fine needle aspiration, biopsy, and imaging techniques. While conventional imaging methods such as X-ray and computed tomography (CT) have proven useful, they exhibit limitations in sensitivity and specificity, especially for soft tissue structures. Magnetic resonance imaging (MRI) provides superior soft tissue contrast, offering additional critical information for differential diagnosis. This article presents a case study of a 29-year-old male with a cervical mass. Advanced dental MRI protocols, including DESS, SPACE-SPAIR, and SPACE-STIR sequences, have significantly enhanced the imaging capabilities of the den-tomaxillofacial region, enabling the generation of high-resolution images of both hard and soft tissues. Especially, MR OPGs have demonstrated the capacity to identify early signs of potential pathology. These protocols have the potential to enhance early detection, thereby con-tributing to accurate diagnosis and effective treatment planning.

Development of quantitative PET/MR imaging for measurements of hepatic portal vein input function: a phantom study

BackgroundAccurate pharmacokinetic modelling in PET necessitates measurements of an input function, which ideally is acquired non-invasively from image data. For hepatic pharmacokinetic modelling two input functions need to be considered, to account for the blood supply from the hepatic artery and portal vein. Image-derived measurements at the portal vein are challenging due to its small size and image artifacts caused by respiratory motion. In this work we seek to demonstrate, using phantom experiments, how a dedicated PET/MR protocol can tackle these challenges and potentially provide input function measurements of the portal vein in a clinical setup.MethodsA custom 3D printed PET/MR phantom was constructed to mimic the liver and portal vein. PET/MR acquisitions were made with emulated respiratory motion. The PET/MR imaging protocol consisted of high-resolution anatomical MR imaging of the portal vein, followed by a PET acquisition in parallel to a dedicated motion-tracking MR sequence. Motion tracking and deformation information were extracted from PET data and subsequently used in PET reconstruction to produce dynamic series of motion-free PET images. Anatomical MR images were used post PET reconstruction for partial volume correction of the input function measurements.ResultsReconstruction of dynamic PET data with motion-compensation provided nearly motion-free series of PET frame data, suitable for image derived input function measurements of the portal vein. After partial volume correction, the individual input function measurements were within a 16.1% error range from the true activity in the portal vein compartment at the time of PET acquisition.ConclusionThe proposed protocol demonstrates clinically feasible PET/MR imaging of the liver for pharmacokinetic studies with accurate quantification of the portal vein input function, including correction for respiratory motion and partial volume effects.

Learning face super-resolution through identity features and distilling facial prior knowledge

Deep learning techniques in electronic surveillance have shown impressive performance for super-resolution (SR) of captured low-quality face images. Most of these techniques adopt facial priors to improve the feature details in the resultant super-resolved images. However, the estimation of facial priors from the captured low-quality images is often inaccurate in real-life situations because of their tiny, noisy, and blurry nature. Thus, the fusion of such priors badly affects the performance of these models. Therefore, this work presents a teacher–student-based face SR framework that efficiently preserves the personal facial structure information in the super-resolved faces. In the proposed framework, the teacher network exploits the facial heatmap-based ground-truth-prior to learn the facial structure that is utilized by the student network. The student network is trained with the identity feature loss for maintaining the identity and facial structure information in reconstructed high-resolution (HR) face images. The performance of the proposed framework is evaluated by conducting the experimental study on standard datasets namely CelebA-HQ and LFW face. The experimental results reveal that the proposed technique conquers the existing methods for the face SR task.

Research on ecological and climate impacts of offshore wind farms based on remote sensing images

Abstract. Offshore wind farm (OWF)’s impact on marine ecological environment has attracted widespread attention since its rapid development. The paper uses high-resolution satellite image data to extract the distribution of offshore wind farms (OWFs) in China based on deep learning method. Chlorophyll-a (CHL-a) concentration and sea surface temperature (SST) were used as indicators to analyze the impact of OWFs’ development. We can then draw the following conclusions: 1) From 2016 to 2022, the number of OWFs in China continues to increase, the growth rate reachs 28% in 2022. 2) The construction of OWFs presents a development trend from near sea to far sea and from shallow sea to deep sea. From 2016 to 2022, the new OWFs are mainly concentrated in sea areas with 5-50 meters water depth, accounting for 84.7 % of the total increase in OWFs. 3) The distribution density of OWFs is negatively correlated with CHL-a concentration and SST, the more OWFs, the greater the impact on CHL-a and SST. In one word, our work analyzed the development trend of OWFs in China and evaluated the impact of OWFs’ expansion on marine ecological environment and climate.

Teleseismic virtual-source reverse time migration of upper crustal structures in the Three Gorges region, China

Summary The Three Gorges (TG) in central China is an earthquake prone region that lacks active-source seismic surveys, hence requiring high-resolution passive seismic imaging to reveal crustal structures in detail. While teleseismic virtual-source reflection (TVR) profiling is effective for imaging gently dipping upper crustal structures, it is unsuitable for mapping steep structures beneath rugged topography in the TG region. Here we develop a teleseismic virtual-source reverse time migration (TV-RTM) to improve the imaging of steep structures. Synthetic tests are conducted to demonstrate the validity and resolution of the TV-RTM method. To mitigate the imaging inaccuracy due to sparse station spacing, we interpolate direct-arrival waveforms to achieve a doubling of the minimally required station spacing from 2 km to 4 km. The TV-RTM images of the upper crustal structure beneath a 2D array in the TG region reveal significant fold and thrust structures that correlate well with the surface geology and tectonic framework. The resolution of the images is assessed using 2D and 3D synthetic models with the station and source geometry of field data. The TV-RTM method provides a new passive seismic solution for studying upper crustal structures in regions that lack active-source seismic data.

Evaluation of Postoperative Outcomes Following Early and Late Palate Repair: A Preclinical Study.

To quantitatively assess the impact of early versus late surgical intervention on midfacial growth using a mouse model. A full-thickness mucoperiosteal flap surgery was performed on newborn (P17) mice and on neonatal (P30) mice. High-resolution micro-computed tomographic imaging coupled with histomorphometric analyses was used to assess craniomaxillofacial growth. Histology and immunohistochemical analyses were used to assess cellular and molecular responses postsurgery. Early surgical intervention at P17 resulted in significant midfacial growth arrest, with pronounced maxillary hypoplasia. Histomorphometric analyses revealed significant (P < 0.05) growth disruptions in the mid-palatal suture complex, including premature removal of the cartilaginous growth plate and its replacement by bone. In the suture itself, cell proliferation was significantly reduced (P < 0.05) compared with controls. The same surgical intervention performed in mice at P30 did not lead to significant midfacial growth arrest. Early surgical intervention in a mouse model mirrors the adverse growth outcomes in children undergoing early cleft repair. Molecular and cellular observations accompanying this midfacial growth arrest may inform therapeutic strategies to mitigate midfacial growth disturbances in patients and highlight the need for refined surgical techniques to minimize adverse growth outcomes.

GAN-Based Dual Image Super Resolution for Satellite Imagery Decreasing Radiometric Uncertainty

Abstract. Super resolution for satellite imagery possesses specific challenges due to its unique feature geometry compared to classic computer vision. Specifically, satellite images contain a high amount of relatively small, distributed high-frequency features that are hard to preserve when sampling up to a higher resolution. General adversarial networks (GANs) are suitable for super resolution tasks but need special attention concerning the geometric and radiometric accuracy of the results. We propose a network for versatile satellite imagery super resolution (VSISR) that focuses on high-frequency detail preservation and radiometric consistency. As a novelty, it is able to utilize a reference high resolution image during inference to lower hallucinations without altering the source image’s radiometric characteristics.A GAN that is already handling well high frequencies in standard computer vision cases is adapted for satellite imagery and supplemented with a mixed pixel approach for data augmentation. Training on a diverse RGB dataset from four satellite missions results in a versatile super resolution model that is optimized to preserve radiometric features and minimize hallucinations. Compared to other neural networks for satellite image super resolution in their respective datasets, VSISR performs in the middle regarding mean PSNR (25.30 dB) and SSIM (0.8098). Nevertheless, it is the first time that, using mixed pixel training on a comparably small dataset, this versatility concerning the satellite data source is achieved while maintaining their unique radiometric traits.

Superconducting nanowire single-photon detector enhanced near-infrared II portable confocal microscopy for tissue imaging with indocyanine green

In this Letter a novel, to our knowledge, approach for near-infrared (NIR) fluorescence portable confocal microscopy is introduced, aiming to enhance fluorescence imaging of biological samples in the NIR-II window. By integrating a superconducting nanowire single-photon detector (SNSPD) into a confocal microscopy, we have significantly leveraged the detection efficiency of the NIR-II fluorescence signal from indocyanine green (ICG), an FDA-approved dye known for its NIR-II fluorescence capabilities. The SNSPD, characterized by its extremely low dark count rate and optimized NIR system detection efficiency, enables the excitation of ICG with 1 mW and the capture of low-light fluorescence signals from deep regions (up to 512 µm). Consequently, our technique was able to produce high-resolution images of bio samples with a superior signal-to-noise ratio, making a substantial advancement in the field of fluorescence microscopy and offering a promising opportunity for future clinical study.

The Rise of Digital Reproduction Against Mechanical Reproduction: “Techno-Nostalgia” in Photography

As a result of advancements in contemporary digital technology, the production tools utilized in art, alongside new instruments that facilitate daily life, are becoming increasingly diverse and sophisticated. The innovations offered by technology provide a wide range of creative opportunities, particularly for artists. However, since the 1990s, there has been a notable tendency towards a retrospective return and mimicry in both daily life and art. This research primarily focuses on the paradox of returning to the past, despite all technological developments and digitalization, as explored through the medium of photography. In this study, the reasons for looking back and mimicking the past in defiance of contemporary realities and technologies are analyzed within the framework of the concept of “tech-nostalgia.” Concrete examples of “tech-nostalgia” in the realm of photography, such as the Lomography movement and Polaroid productions, have been examined in detail. Despite the high-resolution image quality achieved through current technology and the conveniences of the image production process, the reasons for the observed increase in analog photography have been addressed. The investigation delves into how this increase is shaped within the nature of art and photographic aesthetics, and this trend is attempted to be elucidated through psychological and sociological perspectives with relevant examples.

RETRACTION: High-Resolution Imaging of Human Cancer Proteins Using Microprocessor Materials.

M. J. Solares, G. M. Jonaid, W. Y. Luqiu, S. Berry, J. Khadela, Y. Liang, M. C. Evans, K. J. Pridham, W. J. Dearnaley, Z. Sheng and D. F. Kelly, "High-Resolution Imaging of Human Cancer Proteins Using Microprocessor Materials," ChemBioChem, 23, no. 17 (2022), e202200310, https://doi.org/10.1002/cbic.202200310. The above article, published online on 5 July 2022 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor-in-Chief, Ruben Ragg; and Wiley-VCH GmbH. The retraction has been agreed following a thorough peer review process conducted by the author's institution, Penn State. The editors' own independent investigation confirmed that density map for the p53 dimer does not align well with the model for Figures 2B and S3 A. Furthermore, it was found that the coordinate and map files associated with the article available in the Protein Data Bank [PDB accession codes 8F2I (p53 monomer), 8F2H (p53 dimer)] and Electron Microscopy Data Bank [EMDB accession codes EMD28817 (p53 monomer), EMD28816 (p53 dimer)] exhibit poor alignment throughout. In addition, the authors did not provide original research data, maps and models in question, to justify the findings. The editors' own independent investigation confirmed that the conclusions of this manuscript are not sufficiently supported. Author D. F. Kelly responded to our notice of retraction, but did not state their agreement nor disagreement. Author G. M. Jonaid agrees with the retraction. All other authors did not respond to our notice regarding the retraction.

Preparation and Complex Characterisation of Stabilised Gold Nanoparticles: Biodistribution and Application for High Resolution In Vivo Imaging

The Turkevich method was optimized to prepare gold nanoparticles (AuNP) stabilized by polyethyleneglycol (PEG) for µCT. Using various independent modalities, we thoroughly characterized the optimized PEG-AuNPs. Here, we show that PEG-AuNPs are retained in the blood and provide a high contrast in the high-resolution µCT imaging of blood vessels and inner organs. The biodistribution is characterized by prolonged circulation in the blood and accumulation in the liver, spleen and skin. The accumulation of AuNP in the skin resulted in the blue discoloration of eyes and the whole skin. In vitro experiments using a leukemic monocyte THP-1 cell line model expressing high levels of NLRP3 demonstrated that the NLRP3inflammasome was not activated by PEG AuNP. Over 9 months, the mice were scanned by µCT and were in good health. Scans in mice using PEG-stabilized AuNPs in this study were sharper, with a higher contrast, when compared to a commercial contrasting agent at the same dose. The PEG-AuNPs were morphologically and chemically stable for at least two years when stored in the refrigerator.

CsPbBr3-PbSe Perovskite-Chalcogenide Epitaxial Nanocrystal Heterostructures and Their Charge Carrier Dynamics.

Lead halide perovskite and chalcogenide heterostructures which share the ionic and covalent interface bonding may be the possible materials in bringing phase stability to these emerging perovskite nanocrystals. However, in spite of significant successes in the development of halide perovskite nanocrystals, their epitaxial heterostructures with appropriate chalcogenide nanomaterials have largely remained unexplored. Keeping the importance of these materials in mind, herein, epitaxial nanocrystal heterostructures of CsPbBr3-PbSe are reported. The shape remained rhombic dodecahedral-tetrahedral, and the phase retained orthorhombic-cubic for CsPbBr3 and PbSe nanocrystals, respectively. These are synthesized following the standard classical approach of heteronucleations of chalcogenide PbSe with CsPbBr3 perovskite nanostructures and characterized with high-resolution electron microscopic imaging. With an ultrafast study, the hot charge transfer from CsPbBr3 to PbSe is also established. As these are first of its kind nanostructures which are obtained with heteronucleation and growth of chalcogenides on halide perovskites, this finding is expected to open the roadmap for designing other heterostructures which are important for catalysis and photovoltaic applications.

Design of calibration-free RF pulses for T -weighted single-slab 3D turbo-spin-echo sequences at 7T utilizing parallel transmission.

T -weighted turbo-spin-echo (TSE) sequences are a fundamental technique in brain imaging but suffer from field inhomogeneities at ultra-high fields. Several methods have been proposed to mitigate the problem, but were limited so far to nonselective three-dimensional (3D) measurements, making short acquisitions difficult to achieve when targeting very high resolution images, or needed additional calibration procedures, thus complicating their application. Slab-selective excitation pulses were designed for flexible placement utilizing the concept of k -spokes. Phase-coherent refocusing universal pulses were subsequently optimized with the Gradient Ascent Pulse Engineering algorithm and tested in vivo for improved signal homogeneity. Implemented within a 3D variable flip angle TSE sequence, these pulses led to a signal-to-noise ratio (SNR) improvement ranging from 10%to 30% compared to a two-dimensional (2D) T2w TSE sequence employing -shimmed pulses. field inhomogeneities could be mitigated and artifacts from deviations reduced. The concept of universal pulses was successfully applied. We present a pulse design method which provides a set of calibration-free universal pulses (UPs) for slab-selective excitation and phase-coherent refocusing in slab-selective TSE sequences.

Pancreatic cystic neoplasms

Pancreatic cystic lesions represent achallenging heterogeneous entity with a potential risk of malignant transformation. The diagnostics include in particular medical history taking with collection of relevant clinical information and high-resolution imaging, preferably using magnetic resonance imaging (MRI) with MR cholangiopancreatography (MRCP) and/or endoscopic ultrasonography. A differentiation between different cystic entities and identification of risk factors are crucial for making appropriate treatment decisions. Only a small proportion of pancreatic cystic neoplasms require surgery. Pancreatic cystic lesions with a relevant risk of malignancy, such as main duct intraductal papillary mucinous neoplasms (IPMN), mucinous cystic neoplasms (MCN), solid pseudopapillary neoplasms (SPN) and general cystic pancreatic lesions with risk factors regardless of the entity, should be resected, whereas an individualized approach is required for branch duct IPMN and serous cystic neoplasms (SCN) and dysontogenetic cysts require no treatment. Parenchyma-sparing and minimally invasive resection techniques should be preferred whenever possible for resecting pancreatic cystic tumors. Approximately 10% of patients develop recurrences over time.

Enhanced local multi-windows attention network for lightweight image super-resolution

Since the global self-attention mechanism can capture long-distance dependencies well, Transformer-based methods have achieved remarkable performance in many vision tasks, including single-image super-resolution (SISR). However, there are strong local self-similarities in images, if the global self-attention mechanism is still used for image processing, it may lead to excessive use of computing resources on parts of the image with weak correlation. Especially in the high-resolution large-size image, the global self-attention will lead to a large number of redundant calculations. To solve this problem, we propose the Enhanced Local Multi-windows Attention Network (ELMA), which contains two main designs. First, different from the traditional self-attention based on square window partition, we propose a Multi-windows Self-Attention (M-WSA) which uses a new window partitioning mechanism to obtain different types of local long-distance dependencies. Compared with original self-attention mechanisms commonly used in other SR networks, M-WSA reduces computational complexity and achieves superior performance through analysis and experiments. Secondly, we propose a Spatial Gated Network (SGN) as a feed-forward network, which can effectively overcome the problem of intermediate channel redundancy in traditional MLP, thereby improving the parameter utilization and computational efficiency of the network. Meanwhile, SGN introduces spatial information into the feed-forward network that traditional MLP cannot obtain. It can better understand and use the spatial structure information in the image, and enhances the network performance and generalization ability. Extensive experiments show that ELMA achieves competitive performance compared to state-of-the-art methods while maintaining fewer parameters and computational costs.

Detailing organelle division and segregation in Plasmodium falciparum.

The malaria-causing parasite, P. falciparum, replicates through schizogony, a tightly orchestrated process where numerous daughter parasites are formed simultaneously. Proper division and segregation of one-per-cell organelles, like the mitochondrion and apicoplast, are essential, yet remain poorly understood. We developed a new reporter parasite line that allows visualization of the mitochondrion in blood and mosquito stages. Using high-resolution 3D imaging, we found that the mitochondrion orients in a cartwheel structure, prior to stepwise, non-geometric division during last-stage schizogony. Analysis of focused ion beam scanning electron microscopy data confirmed these mitochondrial division stages. Furthermore, these data allowed us to elucidate apicoplast division steps, highlighted its close association with the mitochondrion, and showed putative roles of the centriolar plaques in apicoplast segregation. These observations form the foundation for a new detailed mechanistic model of mitochondrial and apicoplast division and segregation during P. falciparum schizogony and pave the way for future studies into the proteins and protein complexes involved in organelle division and segregation.

Mitigation of DMM-induced stripe patterns in synchrotron X-ray radiography through dynamic tilting.

In synchrotron X-ray radiography, achieving high image resolution and an optimal signal-to-noise ratio (SNR) is crucial for the subsequent accurate image analysis. Traditional methods often struggle to balance these two parameters, especially in situ applications where rapid data acquisition is essential to capture specific dynamic processes. For quantitative image data analysis, using monochromatic X-rays is essential. A double multilayer monochromator (DMM) is successfully used for this aim at the BAMline, BESSY II (Helmholtz Zentrum Berlin, Germany). However, such DMMs are prone to producing an unstable horizontal stripe pattern. Such an unstable pattern renders proper signal normalization difficult and thereby causes a reduction of the SNR. We introduce a novel approach to enhance SNR while preserving resolution: dynamic tilting of the DMM. By adjusting the orientation of the DMM during the acquisition of radiographic projections, we optimize the X-ray imaging quality, thereby enhancing the SNR. The corresponding shift of the projection during this movement is corrected in post-processing. The latter correction allows a good resolution to be preserved. This dynamic tilting technique enables the homogenization of the beam profile and thereby effectively reduces noise while maintaining high resolution. We demonstrate that data captured using this proposed technique can be seamlessly integrated into the existing radiographic data workflow, as it does not need hardware modifications to classical X-ray imaging beamline setups. This facilitates further image analysis and processing using established methods.