Single Imaging Technique Research Articles

Discrimination Model Construction for Non-Lactational Mastitis and Breast Cancer Based on Imaging Features.

Aims/Background The clinical presentation of non-lactational mastitis (NLM) shares similarities with some symptoms and examination results of breast cancer (BC), which can lead to misdiagnosis or delayed treatment. Current studies on breast lesions mostly focus on the diagnostic performance of a single imaging technique. This study aims to construct a discrimination diagnostic model for NLM and BC based on such imaging features as ultrasound and magnetic resonance imaging (MRI) and to validate the application value of the model, assisting clinicians in improving disease diagnosis and refining medical decisions. Methods This study is a retrospective analysis. Clinical data of 108 patients suspected of NLM based on imaging diagnosis, admitted to The First Affiliated Hospital with Nanjing Medical University between May 2018 and August 2023, were collected. Among them, 94 cases were pathologically confirmed as NLM and 14 cases as BC. Univariate and multivariate logistic regression analyses were performed on the patients' clinical data, ultrasound features, and MRI features to select the risk factors for discriminating NLM and BC, and construct a discrimination model. The discrimination performance of the model was analyzed with the receiver operating characteristic (ROC) curve, decision curve analysis (DCA), and calibration curve. Results In the NLM group, there were 24 cases of granulomatous lobular mastitis (25.53%) and 70 cases of plasma cell mastitis (74.47%). In the BC group, there were 2 cases of infiltrating ductal carcinoma, 2 cases of atypical hyperplasia, 3 cases of papillary carcinoma, and 7 cases of ductal carcinoma in situ. Age, internal blood flow, calcification, edge, enhancement characteristics, apparent diffusion coefficient (ADC) values, and time-intensity curve (TIC) type were independent factors for differentiating NLM and BC (p < 0.05). The ROC analysis showed that the area under the curve of the model for discriminating NLM and BC was 0.920. The DCA results showed that the model had high net benefits for discriminating NLM and BC. The calibration curve analysis showed that the model had good consistency with the actual diagnosis of NLM and BC, with a chi-square value of 4.545 and a p-value of 0.155 according to the Hosmer-Lemeshow test. Conclusion Age, internal blood flow, calcification, edge, enhancement characteristics, ADC, and TIC curve types are important factors in distinguishing NLM and BC, and the model based on the above characteristics to distinguish NLM and BC has a high net benefit in distinguishing the two.

Endoscopic Diagnosis and Treatment of Benign Small Bowel Stricture

Benign small bowel strictures can occur in association with various conditions, including small bowel Crohn’s disease, nonsteroidal anti-inflammatory drug-induced enteritis, ischemic enteritis, intestinal tuberculosis, radiation enteritis, postoperative adhesions, and anastomotic strictures. Benign small bowel strictures are classified into two categories, low-grade and high-grade. Low-grade small bowel strictures involve a partial reduction of the internal diameter of the small intestine, causing slight obstruction of the passage of food and digestive fluids without significant bowel obstruction symptoms. By contrast, high-grade small bowel strictures involve a severe narrowing of the intestinal lumen, leading to marked obstruction of the passage of food and digestive fluids and pronounced bowel obstruction symptoms. Small bowel strictures can be diagnosed using various methods, including abdominal plain radiography, abdominal computed tomography, computed tomography enterography, magnetic resonance enterography, balloon-assisted enteroscopy, and abdominal ultrasound. Each diagnostic method has unique advantages and disadvantages as well as differences in diagnostic specificity and sensitivity. Therefore, even if small bowel strictures are not observed using a single imaging technique, their presence cannot be completely excluded. A comprehensive diagnosis that combines clinical information from multiple diagnostic modalities is necessary. Therapeutic approaches for managing small bowel strictures include medical therapy, endoscopic balloon dilation using balloon-assisted enteroscopy, and surgical methods such as strictureplasty and segmental resection. Endoscopic balloon dilation, in particular, can help reduce complications associated with repeated surgeries for strictures.

Highly sensitive and specific detection of human papillomavirus type 16 using CRISPR/Cas12a assay coupled with an enhanced single nanoparticle dark-field microscopy imaging technique

Human papillomavirus (HPV) is a prevalent sexually transmitted pathogen associated with cervical cancer. Detecting high-risk HPV (hr-HPV) infections is crucial for cervical cancer prevention, particularly in resource-limited settings. Here, we present a highly sensitive and specific sensor for HPV-16 detection based on CRISPR/Cas12a coupled with enhanced single nanoparticle dark-field microscopy (DFM) imaging techniques. Ag–Au satellites were assembled through the hybridization of AgNPs-based spherical nucleic acid (Ag-SNA) and AuNPs-based spherical nucleic acid (Au-SNA), and their disassembly upon target-mediated cleavage by the Cas12a protein was monitored using DFM for HPV-16 quantification. To enhance the cleavage efficiency and detection sensitivity, the composition of the ssDNA sequences on Ag-SNA and Au-SNA was optimized. Additionally, we explored using the SynSed technique (synergistic sedimentation of Brownian motion suppression and dehydration transfer) as an alternative particle transfer method in DFM imaging to traditional electrostatic deposition. This addresses the issue of inconsistent deposition efficiency of Ag–Au satellites and their disassembly due to their size and charge differences. The sensor achieved a remarkable limit of detection (LOD) of 10 fM, lowered by 9-fold compared to traditional electrostatic deposition methods. Clinical testing in DNA extractions from 10 human cervical swabs demonstrated significant response differences between the positive and negative samples. Our sensor offers a promising solution for sensitive and specific HPV-16 detection, with implications for cancer screening and management.

PH-responsive albumin-mimetic synthetic nanoprobes for magnetic resonance/fluorescence imaging of thyroid cancer.

The combination of magnetic resonance and fluorescence imaging in dual-modality imaging not only resolves the limitations of conventional single molecular imaging techniques in terms of specificity, sensitivity, and resolution but also expands the possibilities of molecular imaging techniques in diagnostics and therapeutic monitoring. Herein, a novel pH-responsive magnetic resonance/near-infrared fluorescence (MR/NIRF) nanoprobe (MnO2@BSA-Cy5.5) was successfully prepared by biomineralizing manganese dioxide (MnO2) with bovine serum albumin (BSA) while coupling fluorescent dye Cy5.5 for precise tumor detection and visualization. The synthesized MnO2@BSA-Cy5.5 nanoprobes were spherical particles of approximately 22.62 ± 3.31 nm in size, and their relaxation rates and T1 imaging signals were activated-enhanced in an acidic environment. Cytotoxicity assay and hematoxylin and eosin staining demonstrated that MnO2@BSA-Cy5.5 had low cytotoxicity and good biocompatibility. More importantly, active targeting via solid tumor albumin-binding protein receptor and enhanced permeability and retention effect, the probe can be specifically aggregated to the tumor site of the 8305C tumor model and exhibit excellent MR/NIRF imaging properties. Our results show that MnO2@BSA-Cy5.5 has high resolution and sensitivity in tumor imaging and is expected to be applied as an MR/NIRF contrast agent for accurate diagnosis of thyroid cancer.

Single-molecule characterization of salivary protein aggregates from Parkinson's disease patients: a pilot study.

Saliva is a convenient and accessible biofluid that has potential as a future diagnostic tool for Parkinson's disease. Candidate diagnostic tests for Parkinson's disease to date have predominantly focused on measurements of α-synuclein in CSF, but there is a need for accurate tests utilizing more easily accessible sample types. Prior studies utilizing saliva have used bulk measurements of salivary α-synuclein to provide diagnostic insight. Aggregate structure may influence the contribution of α-synuclein to disease pathology. Single-molecule approaches can characterize the structure of individual aggregates present in the biofluid and may, therefore, provide greater insight than bulk measurements. We have employed an antibody-based single-molecule pulldown assay to quantify salivary α-synuclein and amyloid-β peptide aggregate numbers and subsequently super-resolved captured aggregates using direct Stochastic Optical Reconstruction Microscopy to describe their morphological features. We show that the salivary α-synuclein aggregate/amyloid-β aggregate ratio is increased almost 2-fold in patients with Parkinson's disease (n = 20) compared with controls (n = 20, P < 0.05). Morphological information also provides insight, with saliva from patients with Parkinson's disease containing a greater proportion of larger and more fibrillar amyloid-β aggregates than control saliva (P < 0.05). Furthermore, the combination of count and morphology data provides greater diagnostic value than either measure alone, distinguishing between patients with Parkinson's disease (n = 17) and controls (n = 18) with a high degree of accuracy (area under the curve = 0.87, P < 0.001) and a larger dynamic range. We, therefore, demonstrate for the first time the application of highly sensitive single-molecule imaging techniques to saliva. In addition, we show that aggregates present within saliva retain relevant structural information, further expanding the potential utility of saliva-based diagnostic methods.

Single-pixel imaging through non-homogeneous turbid media with adaptive illumination

The presence of scattering media limits the quality of images obtained by optical systems. Single-pixel imaging techniques based on structured illumination are highly tolerant to the presence of scattering between the object and the sensor, but very sensitive when the scattering medium is between the light source and the object. This makes it difficult to develop single-pixel imaging techniques for the case of objects immersed in scattering media. We present what we believe to be a new system for imaging objects through inhomogeneous scattering media in an epi-illumination configuration. It works in an adaptive way by combining diffuse optical imaging (DOI) and single pixel imaging (SPI) techniques in two stages. First, the turbid media is characterized by projecting light patterns with an LED array and applying DOI techniques. Second, the LED array is programmed to project light only through the less scattering areas of the media, while simultaneously using a digital micromirror device (DMD) to project light patterns onto the target using Hadamard basis coding functions. With this adaptive technique, we are able to obtain images of targets through two different scattering media with better quality than using conventional illumination. We also show that the system works with fluorescent targets.

Cardiac Nuclear Imaging Findings in Atypical Variants of Takotsubo Cardiomyopathy

Background: In addition to the typical form resembling the classical Japanese octopus trap, atypical variants of Takotsubo cardiomyopathy (TTC) sparing the left ventricular apex have emerged over the years. The aim of this systematic review is to provide a comprehensive overview of the cardiac nuclear imaging findings in atypical variants. Methods: This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The literature research was carried out online on the Pubmed, Scopus, Central (Cochrane Library), and Web Of Science databases. Results: A total of 14 articles were ultimately selected. Myocardial perfusion scintigraphy was performed in nine studies, followed by 123I-mIBG scintigraphy, 123I-BMIPP scintigraphy, and 18F-FDG PET. In seven cases, a single cardiac nuclear imaging technique was performed, while in the remaining five and two cases, two and three different imaging modalities were, respectively, used. The most common atypical variant of our selection was the midventricular form, followed by reverse/inverted/basal TTC, with only a single case reported of a focal pattern. Conclusions: As the reason why TTC variants occur is still not clear, a deeper understanding of the current knowledge could be the basis for providing more insights into this fascinating disorder and its uncommon manifestations.

Evaluation of antibody-based single cell type imaging techniques coupled to multiplexed imaging of N-glycans and collagen peptides by matrix-assisted laser desorption/ionization mass spectrometry imaging

The integration of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) with single cell spatial omics methods allows for a comprehensive investigation of single cell spatial information and matrisomal N-glycan and extracellular matrix protein imaging. Here, the performance of the antibody-directed single cell workflows coupled with MALDI-MSI are evaluated. Miralys™ photocleavable mass-tagged antibody probes (MALDI-IHC, AmberGen, Inc.), GeoMx DSP® (NanoString, Inc.), and Imaging Mass Cytometry (IMC, Standard BioTools Inc.) were used in series with MALDI-MSI of N-glycans and extracellular matrix peptides on formalin-fixed paraffin-embedded tissues. Single cell omics protocols were performed before and after MALDI-MSI. The data suggests that for each modality combination, there is an optimal order for performing both techniques on the same tissue section. An overall conclusion is that MALDI-MSI studies may be completed on the same tissue section as used for antibody-directed single cell modalities. This work increases access to combined cellular and extracellular information within the tissue microenvironment to enhance research on the pathological origins of disease.Graphical

Hydrogeological structure of a granitic mountain catchment inferred from multi‐method electrical resistivity datasets

AbstractAltered crystalline catchments are complex to study and model, as they present multi‐scale properties that control their hydrogeological behaviour and that are difficult to capture through a single geophysical imaging technique. Several volumes of interest must be sampled in order that both small‐scale (porosity, layering) and large‐scale (bedrock, weathering, faults) heterogeneities can be captured. We propose a geoelectrical model of the Strengbach catchment (Vosges Mountains, France), aiming at identifying the weathered structures and hydrogeological functioning of the aquifer. This is achieved through electrical resistivity tomography (ERT) and Controlled‐Source Audio‐Magnetotelluric (CSAMT) measurements and the use of appropriate measurement set‐ups. Meters‐scale shallow contrasts in the top soil, catchment‐scale shallow contrasts (top 30 m), and large‐scale vertical contrasts (up to 150 m) were resolved through this methodology. A structural interpretation is proposed, based on information provided by borehole measurements (gamma ray, optical images), analysis of sampled waters, and geological mapping. The limits at depth of the weathered and fractured granite, not detected by ERT, are detected by CSAMT. The analysis showed that the weathering state of the granite controls, at first order, the electrical resistivity signal. Shallow geoelectrical signal (first 30 m) is particularly driven by surface conductivity and hence by the clay content, whereas deep geoelectrical signal may arise from both the ionic content of pore waters and the clay content. A structural model is proposed and discussed. Geoelectrical contrasts revealed several qualities of weathered saprolite between the northern and the southern slopes. The inferred structural model and the distribution of weathered and unweathered crystalline units are considered for their respective effect on the hydrogeology, leading to the proposition of a new hydrogeological conceptual model of the catchment.

P03.08.A HIGH-DIMENSIONAL CHARACTERISATION OF THE CELLULAR AND MOLECULAR CHANGES IN THE HUMAN BRAIN AFTER RADIOTHERAPY

Abstract BACKGROUND In the UK ~40,000 intrinsic and metastatic brain tumours are diagnosed each year. Although targeted radiotherapy (RT) is integral to increasing survival of cancer patients, it has significant side-effects, the cellular and molecular mechanisms of which are not fully understood. During RT treatment epigenetic changes occur in the neoplastic tissue, but few studies have assessed these in non-neoplastic brain tissue and results are highly variable. MATERIAL AND METHODS To explore the effects of RT on patient-specific methylation, we retrospectively identified 19 samples, mainly metastatic tumours, that had undergone stereotactic-RT followed by resection, and contained peri-lesional brain tissue, as well as 14 controls. Peri-lesional brain was micro-dissected, followed by DNA methylation profiling and RNA-sequencing. RESULTS Clustering of DNA methylation data showed distinct patterns between the two groups, whilst RNA-seq revealed 1,887 differentially expressed genes. Pathway analysis with GSEA identified differentially represented pathways, including: innate immune system, trans-synaptic signalling, olfactory signalling, regulation of supramolecular fibre organisation, and pattern specification. Computational deconvolution of cellular composition showed increased activated dendritic cells and B-cells, and reduced smooth muscle cells and several sub-sets of astrocytes in the RT samples. CONCLUSION We are currently further investigating these findings using spatial transcriptomics and proteomics to produce the first high-dimensional characterisation of the irradiated human brain. This will also provide the first direct evidence of epigenetic dysregulation after targeted-RT, and assess novel epigenetically-regulated genes, which will be validated with single cell tissue-based imaging techniques. A range of epigenetic-based drugs are undergoing clinical trials and we aim to identify targets for radiomitigation in brain tumour patients.

Evaluation of a deuterated triarylmethyl spin probe for in vivo R2 ∗-based EPR oximetric imaging with enhanced dynamic range.

In this study, we compared two triarylmethyl (TAM) spin probes, Ox071 and Ox063 for their efficacy in measuring tissue oxygen levels under hypoxic and normoxic conditions by R2 *-based EPR oximetry. The R2 * dependencies on the spin probe concentration and oxygen level were calibrated using deoxygenated 1, 2, 5, and 10 mM standard solutions and 2 mM solutions saturated at 0%, 2%, 5%, 10%, and 21% of oxygen. For the hypoxic model, in vivo imaging of a MIA PaCa-2 tumor implanted in the hind leg of a mouse was performed on successive days by R2 *-based EPR oximetry using either Ox071 or Ox063. For the normoxic model, renal imaging of healthy athymic mice was performed using both spin probes. The 3D images were reconstructed by single point imaging and multi-gradient technique was used to determine R2 * maps. The signal intensities of Ox071 were approximately three times greater than that of Ox063 in the entire partial pressure of oxygen (pO2 ) range investigated. The histograms of the tumor pO2 images were skewed for both spin probes, and Ox071 showed more frequency counts at pO2 > 32 mm Hg. In the normoxic kidney model, there was a clear delineation between the high pO2 cortex and the low pO2 medulla regions. The histogram of high-resolution kidney oximetry image using Ox071 was nearly symmetrical and frequency counts were seen up to 55 mm Hg, which were missed in Ox063 imaging. As an oximetric probe, Ox071 has clear advantages over Ox063 in terms of sensitivity and the pO2 dynamic range.

A single camera unit-based three-dimensional surface imaging technique

A single camera unit-based three-dimensional surface imaging technique

Addressing uncertainties in correlative imaging of exogenous particles with the tissue microanatomy with synchronous imaging strategies.

Exposure to exogenous particles is of increasing concern to human health. Characterizing the concentrations, chemical species, distribution, and involvement of the stimulus with the tissue microanatomy is essential in understanding the associated biological response. However, no single imaging technique can interrogate all these features at once, which confounds and limits correlative analyses. Developments of synchronous imaging strategies, allowing multiple features to be identified simultaneously, are essential to assess spatial relationships between these key features with greater confidence. Here, we present data to first highlight complications of correlative analysis between the tissue microanatomy and elemental composition associated with imaging serial tissue sections. This is achieved by assessing both the cellular and elemental distributions in three-dimensional space using optical microscopy on serial sections and confocal X-ray fluorescence spectroscopy on bulk samples, respectively. We propose a new imaging strategy using lanthanide-tagged antibodies with X-ray fluorescence spectroscopy. Using simulations, a series of lanthanide tags were identified as candidate labels for scenarios where tissue sections are imaged. The feasibility and value of the proposed approach are shown where an exposure of Ti was identified concurrently with CD45 positive cells at sub-cellular resolutions. Significant heterogeneity in the distribution of exogenous particles and cells can be present between immediately adjacent serial sections showing a clear need of synchronous imaging methods. The proposed approach enables elemental compositions to be correlated with the tissue microanatomy in a highly multiplexed and non-destructive manner at high spatial resolutions with the opportunity for subsequent guided analysis.

Design and analysis of polygonal mirror-based scan engines for improved spatial frequency modulation imaging.

Spatial frequency modulation imaging (SPIFI) is a structured illumination single pixel imaging technique that is most often achieved via a rotating modulation disk. This implementation produces line images with exposure times on the order of tens of milliseconds. Here, we present a new architecture for SPIFI using a polygonal scan mirror with the following advances: (1) reducing SPIFI line image exposure times by 2 orders of magnitude, (2) facet-to-facet measurement and correction for polygonal scan design, and (3) a new anamorphic magnification scheme that improves resolution for long working distance optics.

Hybrid simultaneous whole-body 2-[18F]FDG-PET/MRI imaging in newly diagnosed multiple myeloma: first diagnostic performance and clinical added value results.

Mixing diagnostic and prognostic data provided by whole-body MRI (WB-MRI) and 2-18F-fluorodeoxyglucose (2-[18F]FDG) positron emission tomography (2-[18F]FDG-PET) from a single simultaneous imaging technique for newly diagnosed multiple myeloma (NDMM) initial workup seems attractive. However, to date, the published data are scarce and this possibility has not been fully explored. In this prospective study, we aimed to explore the diagnostic performance and added clinical value of WB-2-[18F]FDG-PET/MRI imaging in NDMM. All patients with confirmed NDMM at the Nantes University Hospital were prospectively enrolled in this study and underwent WB-2-[18F]FDG-PET/MRI imaging on a 3-T Biograph mMR before receiving treatment. Before imaging, they were considered either as symptomatic or as smoldering MM (SMM). Diagnostic performance of global WB-2-[18F]FDG-PET/MRI imaging, as well as PET and MRI separately for FL and diffuse BMI detection, was assessed and compared in each group. PET-based (maximal standardized uptake value, SUVmax) and MRI-based (mean apparent diffusion coefficient value, ADCmean) quantitative features were collected for FL/para-medullary disease (PMD)/bone marrow and were compared. A total of 52 patients were included in this study. PET and MRI were equally effective at detecting patients with FL (69% vs. 75%) and with diffuse BMI (62% for both) in the symptomatic MM group. WB-2-[18F]FDG-PET/MRI imaging detected FL in 22% of patients with SMM (with a higher diagnostic performance for MRI), resulting in a significant impact on clinical management in this population. SUVmax and ADCmean quantitative features were weakly or not correlated. WB-2-[18F]FDG-PET/MRI could represent the next-generation imaging modality for MM. • Whole-body 2-[18F]FDG-PET/MRI imaging detected at least one focal bone lesion in 75% of patients with symptomatic multiple myeloma, and PET and MRI were equally effective at identifying patients with a focal bone lesion. • Whole-body 2-[18F]FDG-PET/MRI imaging detected a focal bone lesion in 22% of patients with smoldering multiple myeloma (with a higher diagnostic performance for MRI). • MRI had a significant impact on clinical management of smoldering multiple myeloma.

Abstract 2767: Simultaneous 18F-FDG PET/MR imaging for metastases identification in a disseminated human preclinical melanoma model

Abstract Melanoma is a skin cancer at high risk of metastatic progression, hence associated with poorer prognosis. Imaging represents an essential tool to assess tumor stage, but also to monitor disease progression and therapy response. However, a single imaging technique cannot efficiently detect and characterize all metastases. Therefore, we evaluated the potential of simultaneous 18F-FDG PET/MR imaging in preclinical models of disseminated melanoma at different stages. Female Nude and SDRG rats were intravenously injected with CMEL 5 cells, originating from brain metastases of a human melanoma. On day (D) 60, 70, and 80 post-injection, Nude rats were imaged using brain T2-weighted (T2w) 7T MRI and whole-body simultaneous 18F-FDG (10-15 MBq) PET/MR. Furthermore, whole-body and brain T2w MR images were acquired using a 4.7T MRI on D20 and D34 post-injection in SDRG rats. Visual detection and quantitative analysis of lesions were performed on MRI or PET/MR images, and results were confronted with necropsy (melanin pigmented lesions) and gamma counting data. From D60 post-CMEL-5 cell injection, all Nude animals exhibited metastases in one to four different locations. Moreover, most of metastases locations found in clinical setting were detected in our experimental model using simultaneous 18F-FDG PET/MR imaging, even allowing the observation of brain lesions on T2w MR images. MRI further allowed precise contouring of each organ of interest to effectively identify bone, lung, adrenal and spleen metastases with enhanced 18F-FDG uptake. Additionally, PET image quantification in adrenals was consistent with gamma counting results. As anticipated, small lesions below PET spatial resolution limit (i.e. &amp;lt;1 mm) were not detected by imaging. SDRG rats displayed a faster and more homogenous tumor spread in brain, lungs and liver on MR images, while more metastases were seen during autopsy (additional spreading to pancreas, adrenals, reproductive system, bones, lymph nodes and skin). The experimental model of disseminated CMEL-5 melanoma in Nude rats demonstrates its ability to mimic the human pathology. Hence, it appears to be a promising tool to monitor therapy response and potentially recognize progression from pseudo-progression. Simultaneous PET/MR imaging has shown to be more effective than stand-alone techniques in detecting melanoma dissemination, except for brain and small lesions for which the PET data are altered by partial volume effect. Thus, by complementing previously acquired MR images from the novel SDRG rat model with simultaneously acquired PET images, we could also provide insights on this promising metastatic model. Citation Format: Alexandra Oudot, Peggy Provent, Alan Courteau, Nicolas Hoffmann, Melanie Guillemin, Jordan Longin, Sarah Belderbos, Bertrand Collin, Marc Hillairet de Boisferon, Alexandre Cochet, Cyril Berthet. Simultaneous 18F-FDG PET/MR imaging for metastases identification in a disseminated human preclinical melanoma model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2767.

Advances in Intravascular Ultrasound

Since its inception, intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have played a significant role in evaluating the pathophysiology of coronary artery disease (CAD) guiding the interventional and medical management of CAD improving outcomes in patients. Although the benefits of each of these modalities have been proven, due to some limitations, no single intravascular imaging technique has been proven to provide a detailed and complete evaluation of all CAD lesions. The use of different intravascular imaging modalities sequentially may lead to complications, which are cumbersome, consume time, and add financial burden to the patient. Recently, hybrid imaging catheters that combine OCT and IVUS benefits have been developed to limit these problems. Intravascular imaging techniques we are using currently have some drawbacks that hinder accurate assessment of plaque morphology and pathobiology as demonstrated in many histological studies, causing difficulty in identifying high-risk plaques. To overcome these limitations, great efforts have been put into developing hybrid, dual-probe catheters by combining imaging modalities to get an accurate analysis of plaque characteristics, and high-risk lesions. At present, many dual-probe catheters are available including combined IVUS-OCT, near-infrared spectroscopy-IVUS that is available commercially, the OCT-near infrared fluorescence (NIRF) molecular imaging, IVUS-NIRF, and combined fluorescence lifetime-IVUS imaging. Application of this combined multimodal imaging in clinical practice overcomes the limitations of standalone imaging and helps in providing a comprehensive and accurate visualization of plaque characteristics, composition, and plaque biology. The present article summarizes the advances in hybrid intravascular imaging, analyses the technical hindrances that should be known to have a use in the different clinical circumstances, and the till date shreds of evidence available from their first clinical application aiming to bring these modalities into the limelight and their potential role in the study of CAD.

Characterization of extracellular vesicle and virus-like particles by single vesicle tetraspanin analysis

Extracellular vesicles (EVs) are nano-sized membranous particles secreted by cells. EVs have been classified into subpopulations according to their presumed biogenesis pathway, but their detailed biogenesis mechanisms still need to be fully elucidated. Enveloped viruses are another type of cell-derived nano-vesicles, and their biogenesis processes are much better known than that of EVs. Recently, studies on the similarity between enveloped viruses and EVs have been increasingly reported. The biogenesis of EVs could be better understood if these similarities are adequately investigated. In this study, we utilized a single vesicle imaging technique to visualize the protein expressions of individual nano-sized vesicles and analyzed expression patterns within single vesicles. Using this technique, we identified unique tetraspanin expression patterns in single EVs and that these patterns were closely related to their subcellular origins. The expression of CD9 or CD81 in EVs implied that they originated from the plasma membrane, and the expression of CD63 in EVs implied that they originated from endosomal organelles. We further analyzed the tetraspanin expressions of two different types of virus-like particles (VLPs) and demonstrated that the HIV-Gag-induced VLPs were more similar to EVs than SARS-CoV-2-NP/M/E-induced VLPs. In addition, HIV-Gag-GFP-expressing VLPs were highly colocalized with CD9, CD63, and CD81 signals, whereas SARS-CoV-NP-GFP-expressing VLPs were not. Based on these observations, we could assume that tetraspanin-expressing EVs might be produced through a similar process by which HIV is produced.

The Role of Multimodality Imaging Approach in Acute Aortic Syndromes: Diagnosis, Complications, and Clinical Management

Acute aortic syndromes are life-threatening conditions with high morbidity and mortality. The principal pathological feature is acute wall damage with possible evolution towards aortic rupture. Accurate and timely diagnosis is mandatory to avoid catastrophic consequences. Indeed, misdiagnosis with other conditions mimicking acute aortic syndromes is associated with premature death. In this view, cardiovascular imaging is necessary for the correct diagnosis and management. Echocardiography, computed tomography, magnetic resonance imaging, and aortography allow for diagnosis, guarantee immediate treatment, and detect associated complications. Multimodality imaging is essential in the diagnostic work-up to confirm or rule out acute aortic syndromes. The aim of this review is to highlight the contemporary evidence on the role of single cardiovascular imaging techniques and multimodality imaging in the diagnosis and management of acute aortic syndromes.

Time-space united coding spread spectrum single photon counting imaging method

In this paper, we demonstrate a new imaging architecture called time-space united coding spread spectrum single photon counting imaging technique by combining the space coding based single-pixel imaging technology and spread spectrum time coding based scanning imaging technology. This method has the advantages of range ambiguity-free and large time-bandwidth product. Under the interference of noise, this method can accurately restore depth images. In this work, the time-space united correlation nonlinear detection model based on single photon detection, forward imaging model and signal-to-noise ratio model is derived, and the depth image is restored by convex optimization inversion algorithm. The theoretical model and simulation experiments show that compared with the traditional single pixel imaging method based on spatial coding, this method improves the quality of scene reconstruction. Using m-sequence as time coding, imaging has higher noise robustness. In addition, compared with the traditional space coding single pixel imaging technology, the imaging mean square error of the proposed method is reduced by 4/5 and the imaging mean squared error is reduced by 9/10 after introducing the second correlated method. The proposed imaging architecture in this paper may provide a new path for non-scanning lidar imaging methods.