Imaging Methods Research Articles

Diagnostic Performances of 18F-Fluorocholine PET/CT as First-Line Functional Imaging Method for Localization of Hyperfunctioning Parathyroid Tissue in Primary Hyperparathyroidism

Rationale and ObjectivesThis study evaluated the diagnostic performance of 18F-fluorocholine (FCH) PET/CT as the first-line functional imaging method for preoperative localization of hyperfunctioning parathyroid glands (HPGs) in patients with primary hyperparathyroidism (PHPT). Materials and MethodsThis retrospective single-centre study included 80 consecutive patients with PHPT, referred for FCH PET/CT between January 2018 and July 2022, and who subsequently underwent surgery. The diagnostic performance of FCH PET/CT was compared to histological results for per-lesion analysis, and to postoperative resolution of biochemical PHPT for per-patient analysis. Results18F-FCH-PET/CT revealed 95 positive foci in 77/80 patients and was negative in 3/80 patients. Postoperative resolution of HPT was obtained in 67/80 patients (84%). Per-lesion analysis showed 80 true positives, 5 true negatives, 11 false negatives and 8 false positives. Seven PET positive foci could not be compared with histology. In a first per-lesion analysis, excluding these 7 anomalies, sensitivity and positive predictive value (PPV) of FCH PET/CT were 88% (95% CI: 79-94) and 91% (95% CI: 87-94), respectively. In a second per-lesion analysis considering the 7 anomalies as false positives (maximum bias analysis), PPV was 84% (95% CI: 80%-87%). By per-patient analysis, FCH PET/CT correctly identified and located all pathological glands in 56/80 (70%, 95% CI: 59-80) patients. Conclusion18F-Fluorocholine PET/CT appears to be an effective pre-surgical imaging method for localization of hyperfunctioning parathyroid tissue in patients with PHPT.

A Comprehensive Review of the Recent Advancements in Imaging Segmentation and Registration Techniques for Glioblastoma and Focusing on the Utilization of Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) Scans.

The most common primary malignant brain tumor is glioblastoma. Glioblastoma Multiforme (GBM) diagnosis is difficult. However, image segmentation and registration methods may simplify and automate Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scan analysis. Medical practitioners and researchers can better identify and characterize glioblastoma tumors using this technology. Many segmentation and registration approaches have been proposed recently. Note that these approaches are not fully compiled. This review efficiently and critically evaluates the state-of-the-art segmentation and registration techniques for MRI and CT GBM images, providing researchers, medical professionals, and students with a wealth of knowledge to advance GBM imaging and inform decision-making. GBM's origins and development have been examined, along with medical imaging methods used to diagnose tumors. Image segmentation and registration were examined, showing their importance in this difficult task. Frequently encountered glioblastoma segmentation and registration issues were examined. Based on these theoretical foundations, recent image segmentation and registration advances were critically analyzed. Additionally, evaluation measures for analytical efforts were thoroughly reviewed.

Synthesis and Pesticidal Activities of Ester Derivatives of the Labdane Diterpenoid Andrographolide at the C-3 Position Containing the Isoxazoline Fragment and Their Toxicology Study against Tetranychus cinnabarinus Boisduval.

Due to the long-term overuse of chemical pesticides, serious resistance and negative problems on human health and the ecological environment have appeared. To develop plant-product-based pesticide candidates, a series of novel andrographolide ester derivatives containing the isoxazoline skeleton were prepared at the C-3 position. Their pesticidal activities were evaluated against three typical pests such as Mythimna separata Walker, Aphis citricola Van der Goot, and Tetranychus cinnabarinus Boisduval. Against M. separata, compounds Ik, IIf, IIg, and IIk showed 1.6-1.8 times insecticidal activity compared to that of andrographolide; against A. citricola, compounds 6, Ih, and IIh possessed 3.7-3.9-fold aphicidal activity compared to that of andrographolide; against T. cinnabarinus, compounds Ib, Ig, and IIk exhibited 7.4-9.1-fold promising acaricidal activity compared to that of andrographolide. It is worth mentioning that effects of IIk on morphological changes of the treated mite cuticle layer structures were observed by the scanning electron microscope imaging method. Compound IIk can be studied as a pesticidal lead for further structural modification.

Evidence-Based Data on the Diagnostic Role and Clinical Usefulness of [18F]FDG PET/CT in Endocarditis and Cardiac Device Infections.

Infective endocarditis and infection of cardiac devices are conditions characterized by high morbidity and mortality, thus requiring a prompt diagnosis. Advanced imaging modalities are often required in the management of infectious endocarditis according to guidelines. The aim of this review is to collect and describe evidence-based knowledge about the diagnostic role and clinical usefulness of [18F]FDG PET/CT in endocarditis and cardiac device infections based on published systematic reviews and meta-analyses on this topic and on recent guidelines. [18F]FDG PET/CT is recommended only in selected cases. This imaging method has good diagnostic accuracy in detecting prosthetic valve endocarditis and cardiac device infection. Furthermore, it can identify extra-cardiac infectious foci changing the clinical management in a significant percentage of cases.

The Role of HE4 in the Follow-Up of Advanced Ovarian, Fallopian Tube, and Primary Peritoneal Cancer—CEEGOG OX-01 Study

Background: Ovarian, fallopian tube, and primary peritoneal cancers often share clinical characteristics and are typically diagnosed at advanced stages due to nonspecific symptoms. The utility of tumor markers, particularly CA125 and HE4, in the diagnosis and follow-up of these cancers remains an area of active investigation. Objectives: The CEEGOG (Central and Eastern European Gynecologic Oncology Group) OX-01 study aimed to evaluate HE4’s role alongside CA125 in follow-up for advanced-stage ovarian, fallopian tube, and primary peritoneal cancers. It assessed the potential for detecting recurrence using marker elevation and imaging methods, examining the necessity of dynamic monitoring and current cut-off values’ accuracy for early relapse detection. Methods: In this multicenter prospective cohort study, 117 eligible patients with Stage III–IV cancers were included. Patients had elevated CA125 or HE4 at diagnosis and achieved complete remission after first-line treatment. HE4 and CA125 levels were monitored every 3–4 months in the first two years and every six months thereafter. CT scans were performed if markers exceeded set thresholds or increased by over 20%. Results: During a median follow-up of 13.7 months, 73% of patients relapsed. Median HE4 levels were significantly higher in relapsed patients. A 10 IU/mL increase from baseline in CA125 had a sensitivity of 83% and specificity of 93%, while a 15 pmol/L increase in HE4 had a sensitivity of 74% and specificity of 92% for predicting relapse up to three months before CT scan detection. Conclusions: The study found that dynamic changes in HE4 and CA125 levels, rather than predefined cut-off values, are crucial for early relapse detection. These markers may offer a significant lead time over imaging, potentially enabling earlier intervention. Further research is needed to validate these findings.

Development of a Hyperspectral Imaging Protocol for Painting Applications at the University of Seville

In the last decade, the hyperspectral imaging (HSI) method allowed performing non-invasive analysis in the field of cultural heritage. However, a considerable limitation was given by redundant and time-consuming features, with the necessary application of statistical algorithms and image-processing tools to extract relevant information. In this study, the Centro Nacional de Aceleradores (CNA) and the Group of Interdisciplinary Physics (GFI) of the School of Engineering (ETSI) of the University of Seville tested the application of three different hyperspectral cameras in the visible and near-infrared (VNIR) and short-wave infrared (SWIR) range for the investigation of an ancient painting. A reference-based procedure was realised to build a starting personal library and to evaluate the best working conditions for non-invasive and non-destructive characterisation with data treatment using the commercially available software Evince® and Specim IQ® to apply, respectively, the Principal Component Analysis (PCA) model functions and the classification method. The evaluation of the protocol was tested by acquiring complementary information by X-ray fluorescence (XRF), Ultraviolet Luminescence (UVL) imaging, and Infrared Reflectography (IRR). This exploration established a simplified protocol to analyse the large collection of paintings of the Archbishop’s Palace and the Cathedral of Seville.

Repeatability and Reproducibility of pseudo-Continuous Arterial Spin Labeling Measured Brain Perfusion in Healthy Volunteers and Glioblastoma Patients.

Arterial spin labeled (ASL) MRI has gained recognition as a quantitative perfusion imaging method for managing patients with brain tumors. Limited studies have so far investigated the reproducibility of ASL-derived perfusion in patients with brain tumors. This study aims to evaluate intrasession repeatability and intersession reproducibility of perfusion measurements using 3D pseudo-continuous ASL (pCASL) with Cartesian TSE (TSE-CASPR) in healthy volunteers (HV) and glioblastoma (GBM) patients at 3 Tesla and compare against 3D pCASL with GRASE. This prospective study (NCT03922984) was approved by the institutional review board and written informed consent was obtained from all subjects. HV underwent repeated pCASL evaluations 2-4 weeks apart between November 2021 and October 2022. GBM patients were recruited for longitudinal MRI from September 2019 to February 2023. Intrasession repeatability (HV and GBM) and intersession reproducibility (HV only) of pCASL were assessed using linear regression, Bland-Altman analyses, intraclass correlation coefficient (ICC) with 95% confidence interval (CI), and within-subject coefficients of variation (wsCV). Twenty HV (9 men, age: 25.1±1.7 years, range 23-30 years) and 21 GBM patients (15 men; age: 59.8±14.3 years, range 28-81 years) were enrolled. Within imaging session, 3D pCASL measured perfusion with TSE-CASPR and GRASE respectively achieved high R2 values (0.88-0.95; 0.93-0.96), minimal biases (-0.46 to 0.81; -0.08 to 0.35 mL/100g/min), high ICC [95% CI] (0.96-0.98 [0.94-0.98]; 0.96-0.98 [0.92-0.99]), and low wsCV (6.64%-9.07%; 5.20%-8.16%) in HV (N=20) and GBM patients (N=21). Across imaging session, 3D pCASL in HV (N=20) achieved high R2 values (0.71; 0.82), minimal biases (-1.2; -0.90 mL/100g/min), high ICC [95% CI] values (0.85 [0.81-0.89]; 0.90 [0.87-0.93]), and low wsCV values (13.82%; 9.98%). Our study demonstrated excellent intrasession repeatability of 3D pCASL measured cerebral perfusion in HV and GBM patients and good to excellent intersession reproducibility in HV. 3D pCASL with GRASE performed slightly better than 3D pCASL with TSE-CASPR in HV; however, in GBM patients, 3D pCASL with TSE-CASPR showed better performance in tumor regions with nearly twofold higher SNR. ASL measured perfusion could serve as a non-contrast quantitative imaging biomarker to facilitate the management of GBM patients. ASL = arterial spin labeling; pCASL = pseudo-continuous arterial spin labeling; GBM = glioblastoma; CBF = cerebral blood flow; CASPR = Cartesian acquisition with spiral profile reordering; GRASE = gradient and spin echo; NAGM = normal-appearing gray matter.

Spatial analysis by current multiplexed imaging technologies for the molecular characterisation of cancer tissues.

Tumours are composed of tumour cells and the surrounding tumour microenvironment (TME), and the molecular characterisation of the various elements of the TME and their interactions is essential for elucidating the mechanisms of tumour progression and developing better therapeutic strategies. Multiplex imaging is a technique that can quantify the expression of multiple protein markers on the same tissue section while maintaining spatial positioning, and this method has been rapidly developed in cancer research in recent years. Many multiplex imaging technologies and spatial analysis methods are emerging, and the elucidation of their principles and features is essential. In this review, we provide an overview of the latest multiplex imaging techniques by type of imaging and staining method and an introduction to image analysis methods, primarily focusing on spatial cellular properties, providing deeper insight into tumour organisation and spatial molecular biology in the TME.

Unlocking the potential of simulated hyperspectral imaging in agro environmental analysis: a comprehensive study of algorithmic approaches

This study focuses on identifying and evaluating the severity of powdery mildew disease in tomato plants. The uniqueness of this work lies in combining the imaging and advanced deep learning methods to develop a technique that transforms Red Green Blue (RGB) images into Simulated Hyperspectral Images (SHSI) to perform spectral and spatial analysis for precise detection and assessment of powdery mildew severity, thereby enhancing disease management. Furthermore, this research evaluates three advanced pre-trained VGG16 models, ResNet50 and EfficientNet-B7 algorithms for image preprocessing and feature extraction. Extracted features are passed to a neural network generator model to convert RGB image features into SHSIs, providing insights into the spectrum. This method enables the image analysis to perform assessments from SHSIs for health classification using Normalized Difference Vegetation Index (NDVI) values, which are meticulously compared with accurate hyperspectral data using metrics like mean absolute error (MAE) and root mean squared error (RMSE). This strategy enhances precision farming, environmental monitoring, and remote sensing accuracy. Results show that ResNet50’s architecture offers a robust framework for this study’s spectral and spatial analysis, making it a suitable choice over VGG16 and EfficientNet-B7 for transforming RGB images into SHSI. These simulated hyperspectral images offer a scalable and affordable approach for precise assessment of crop disease severity.

Prognostic value of interim [68Ga]Ga-DOTA-TOC PET/CT in patients with neuroendocrine tumour who underwent peptide receptor radionuclide therapy.

This study evaluated the prognostic value of basal and interim [68Ga]Ga-DOTA-TOC PET/CT in patients with locally advanced or metastatic neuroendocrine tumour (NET) who received peptide receptor radionuclide therapy (PRRT). Patients with NET who received PRRT with [177Lu]Lu-DOTA-TATE at our institution were retrospectively reviewed. Among them, patients who underwent both basal and interim (after two cycles of PRRT) [68Ga]Ga-DOTA-TOC PET/CT were included. Alongside clinicopathologic parameters, PET parameters of maximum standardised uptake value (SUVmax), tumour-to-liver ratio (TLR), whole tumour volume (WTV) and total receptor expression (TRE: WTV multiplied by mean standardised uptake value) were obtained from basal and interim [68Ga]Ga-DOTA-TOC PET/CT, and their proportional changes (∆) were assessed for associations with progression-free survival (PFS) using Kaplan-Meier analysis, log-rank tests, and a Cox proportional-hazards regression model. Twenty-four patients were finally included (10 men and 14 women, median age of 56.5 years, age range 32-74 years). Among them, 16 patients (66.7%) experienced disease progression. In univariate analysis, high ∆WTV (≥ -10%, hazard ratio [HR] = 3.053 [1.003-9.289], p = 0.049) and high ∆TRE (≥ -21%, HR = 3.567 [1.144-11.122], p = 0.028) were significantly associated with shorter PFS. In multivariate analyses adjusted for WHO grade, high ∆WTV (HR = 3.345 [1.055-10.601], p = 0.043) and high ∆TRE (HR = 3.894 [1.194-12.695], p = 0.024) were significant predictors of shorter PFS. The study demonstrates that basal and interim [68Ga]Ga-DOTA-TOC PET/CT scans, through proportional changes in WTV and TRE, effectively predict PFS in neuroendocrine tumour patients receiving PRRT. Question Peptide receptor radionuclide therapy is utilised for patients with somatostatin receptor-positive well-differentiated neuroendocrine tumours; however, prognostic predictors are not well established. Findings Progression-free survival was significantly associated with the proportional change in whole tumour volume and total receptor expression between basal and interim [68Ga]Ga-DOTA-TOC PET/CT. Clinical relevance Interim [68Ga]Ga-DOTA-TOC PET/CT can serve as a valuable imaging method to predict prognosis of peptide receptor radionuclide therapy.

Aneurism of the left portal vein branch in a teenager - a rare clinical case

The authors presented their own clinical observation of an aneurysm of the left portal vein branch in a teenager with a long-term asymptomatic course. Reduced serum concentrations of ceruloplasmin and α-1-antitrpsin made diagnostic search difficult, which could lead to incorrect therapeutic decisions. However, the results of imaging methods allowed us to establish the root cause of liver damage and its cirrhotic transformation. Vascular aneurysms of the portal vein system are a very rare pathology, and it should be taken into account in the differential diagnostic algorithm while excluding other, more obvious causes of liver pathology.

A time-division achromatic imaging method for liquid crystal lens

A time-division achromatic imaging method for liquid crystal lens

Surface Wave Imaging Method Based on Spatial Autocorrelation Principle for Mining Microseismic Monitoring

Surface Wave Imaging Method Based on Spatial Autocorrelation Principle for Mining Microseismic Monitoring

Evaluation of the Normal Measurements of Orbital Structures in Healthy Adult Individuals by Using a Magnetic Resonance Imaging Method

Background: This study aims to determine the normal values of orbital structures according to sex in healthy adults. Methods: Diameters of extraocular muscles, the width of the optic nerve sheath diameter, the length of the inter-zygomatic line, ocular bulb length, and globe position were measured in the T1-weighed MR (magnetic resonance) images in 204 orbits of 102 individuals. Results: The mean values of the diameters of the extraocular muscles in males and females were as follows: medial rectus, 3.96 ± 0.52 and 3.58 ± 0.53 mm; lateral rectus, 3.47 ± 0.61 and 3.15 ± 0.48 mm; inferior rectus, 4.47 ± 0.53 and 4.07 ± 0.48 mm; superior rectus, 4.44 ± 0.64 and 4.01 ± 0.56 mm; and superior oblique, 3.68 ± 0.49 and 3.45 ± 0.44 mm. The length of the interzygomatic line in males and females were 102.68 ± 3.89 and 96.95 ± 3.4 mm, the ocular bulb length was 23.33 ± 1.32 and 22.83 ± 1.1 mm, the globe position was 7.66 ± 1.33 and 7.3 ± 1.39 mm, and the width of the optic nerve sheath diameter was 4.65 ± 0.62 and 4.28 ± 0.51 mm, respectively. All measurements were significantly greater for males than for females (p < 0.05). Conclusions: We believe that a practical and quantitative method will be provided by this study for the diagnosis and determination of the normative values of orbital structures.

Nanotubules and Cellular Communication in Trabecular Meshwork Cells.

Glaucoma causes dysfunction to tissues located in the anterior and posterior eye. In the anterior eye, the trabecular meshwork (TM) is the site of pathogenesis, where decreased TM cell numbers and alterations to the amount and composition of extracellular matrix hinder outflow of aqueous humor fluid from the anterior chamber. This causes intraocular pressure (IOP) elevation. Elevated IOP, a main risk factor for primary open-angle glaucoma, damages the axons of retinal ganglion cells in the posterior eye, which ultimately leads to blindness. Thus, clinical treatment paradigms for glaucoma are focused on reducing IOP. Normotensive IOPs are established by balancing the production of aqueous fluid from the ciliary body with drainage through the TM to Schlemm's canal. When IOP becomes elevated, TM cells coordinate a homeostatic response to lower IOP, which requires effective and efficient cellular communication. Tunneling nanotubes (TNTs) are transient specialized structures that allow cells to communicate with one another. Actin-rich tubes allow direct transmission of signals and cargoes between cells. This is important to overcome limitations of diffusion-based signaling in aqueous environments such as the anterior eye. Here, we describe a live-cell imaging method for monitoring TNTs in primary TM cells.

Long-Range Three-Dimensional Tracking of Nanoparticles Using Interferometric Scattering Microscopy.

Tracking nanoparticle movement is highly desirable in many scientific areas, and various imaging methods have been employed to achieve this goal. Interferometric scattering (iSCAT) microscopy has been particularly successful in combining very high spatial and temporal resolution for tracking small nanoparticles in all three dimensions. However, previous works have been limited to an axial range of only a few hundred nanometers. Here, we present a robust and efficient measurement and analysis strategy for three-dimensional tracking of nanoparticles at high speed and with nanometer precision. After discussing the principle of our approach using synthetic data, we showcase the performance of the method by tracking gold nanoparticles with diameters ranging from 10 to 80 nm in water, demonstrating an axial tracking range from 4 μm for the smallest particles up to over 30 μm for the larger ones. We point out the limitations and robustness of our system across various noise levels and discuss its promise for applications in cell biology and material science, where the three-dimensional motion of nanoparticles in complex media is of interest.

Carbon dots for pathogen detection and imaging: recent breakthroughs and future trends.

As a class of carbon-based nanomaterials, carbon dots (CDs) have gained a lot of interest for a variety of applications. They offer distinctive optical, chemical, and structural characteristics along with favourable attributes such as low cost, availability of abundant functional groups, remarkable chemical inertness, high stability, exceptional biocompatibility, and ecofriendliness. This review discusses synthesis methods, structural characteristics, and surface modifications of CDs, specific for pathogen detection. Furthermore, it delves into the mechanisms that govern the interaction between pathogens and CDs. In addition, the study explores the use of CDs in a number of detection modalities, such as optical, electrochemical, and electrochemiluminescence, emphasising real-time pathogen monitoring. Moreover, both the challenges and opportunities related to the application of CDs-based detection and imaging methods are highlighted in field and clinical contexts.

Development of crystal optics for X-ray multi-projection imaging for synchrotron and XFEL sources.

X-ray multi-projection imaging (XMPI) is an emerging experimental technique for the acquisition of rotation-free, time-resolved, volumetric information on stochastic processes. The technique is developed for high-brilliance light-source facilities, aiming to address known limitations of state-of-the-art imaging methods in the acquisition of 4D sample information, linked to their need for sample rotation. XMPI relies on a beam-splitting scheme, that illuminates a sample from multiple, angularly spaced viewpoints, and employs fast, indirect, X-ray imaging detectors for the collection of the data. This approach enables studies of previously inaccessible phenomena of industrial and societal relevance such as fractures in solids, propagation of shock waves, laser-based 3D printing, or even fast processes in the biological domain. In this work, we discuss in detail the beam-splitting scheme of XMPI. More specifically, we explore the relevant properties of X-ray splitter optics for their use in XMPI schemes, both at synchrotron insertion devices and XFEL facilities. Furthermore, we describe two distinct XMPI schemes, designed to faciliate large samples and complex sample environments. Finally, we present experimental proof of the feasibility of MHz-rate XMPI at the European XFEL. This detailed overview aims to state the challenges and the potential of XMPI and act as a stepping stone for future development of the technique.

A novel enhancing method for terahertz imaging of integrated circuits flaw detection

This research paper addresses the current gap in understanding the intricate damage types within packaged integrated circuits (ICs). We introduce a novel and multiscale latent low-rank representation (M-LatLRR) methodology, meticulously tailored to enhance the quality of terahertz (THz) IC images and reveal latent features. By integrating THz imaging with our proposed M-LatLRR method, we aim to facilitate the precise identification of damage types within inside the packaged ICs. Firstly, the multiscale Gaussian functions are used to remove the blur and the components are obtained via averaging. Secondly, the image matrices are utilized to extract base matrices and detail matrices. With LatLRR, the multiscale detail matrices are extracted at several representation levels. The final enhanced image is reconstructed by average strategy for dealing with the detail and pre-enhancement parts. The M-LatLRR framework is universal and can be effectively applied to extract multi-level features of packaged IC images. In a comparative analysis, our method demonstrates superior capabilities in determining the failure types of fractured wire bonds, cracks, and delamination of the dielectric layer, outperforming alternative methodologies.

Zero-echo-time sequences in highly inhomogeneous fields.

Zero-echo-time (ZTE) sequences have proven a powerful tool for MRI of ultrashort tissues, but they fail to produce useful images in the presence of strong field inhomogeneities (14 000 ppm). Here we seek a method to correct reconstruction artifacts from non-Cartesian acquisitions in highly inhomogeneous , where the standard double-shot gradient-echo approach to field mapping fails. We present a technique based on magnetic field maps obtained from two geometric distortion-free point-wise (SPRITE) acquisitions. To this end, we employ three scanners with varying field homogeneities. These maps are used for model-based image reconstruction with iterative algebraic techniques (ART). For comparison, the same prior information is fed also to widely used Conjugate Phase (CP) algorithms. Distortions and artifacts coming from severe inhomogeneities, at the level of the encoding gradient, are largely reverted by our method, as opposed to CP reconstructions. This holds even close to the limit where intra-voxel bandwidths (determined by inhomogeneities, up to 1.2 kHz) are comparable to the encoding inter-voxel bandwidth (determined by the gradient fields, 625 Hz in this work). We have benchmarked the performance of a new method for ZTE imaging in highly inhomogeneous magnetic fields. For example, this can be exploited for dental imaging in affordable low-field MRI systems, and can be expanded for arbitrary pulse sequences and extreme magnet geometries, as in, for example, single-sided MRI.