The field of biomedical imaging has been revolutionized by deep learning techniques.This special issue is focused on the theme of“AI-based Image Analysis”.Because there are so many conferences and journals in this f...The field of biomedical imaging has been revolutionized by deep learning techniques.This special issue is focused on the theme of“AI-based Image Analysis”.Because there are so many conferences and journals in this field,our special issue can only be a small snapshot of a much bigger and highly dynamic picture.In this special issue,we present six papers that highlight the power of deep learning in solving challenging biomedical imaging and image analysis problems.展开更多
Computational biomedical imaging lies at the intersection of physics,computer science,and biomedicine,aiming to produce visual representations of biological or physiological phenomena that may be otherwise imperceptib...Computational biomedical imaging lies at the intersection of physics,computer science,and biomedicine,aiming to produce visual representations of biological or physiological phenomena that may be otherwise imperceptible to measuring instruments.Over the last few decades,breakthroughs in imaging physics-as evidenced by modalities like magnetic resonance imaging(MRI),computed tomography(CT),ultrasound,optical microscopy,and endoscopy-have profoundly impacted the way clinicians visualize and understand living systems.展开更多
Perface In his 1790 book,The Critique of Judgment,Immanuel Kant asserted that“Life is a self-organized and self-producing process,and the existence and form of its parts are only possible through their relation to th...Perface In his 1790 book,The Critique of Judgment,Immanuel Kant asserted that“Life is a self-organized and self-producing process,and the existence and form of its parts are only possible through their relation to the whole…”.However,such a holistic and complex perspective is challenging to separate and study objectively.展开更多
The rapid development of super-resolution microscopy has made it possible to observe subcellular structures and dynamic behaviors in living cells with nanoscale spatial resolution, greatly advancing progress in life s...The rapid development of super-resolution microscopy has made it possible to observe subcellular structures and dynamic behaviors in living cells with nanoscale spatial resolution, greatly advancing progress in life sciences. As hardware technology continues to evolve, the availability of new fluorescent probes with superior performance is becoming increasingly important. In recent years, fluorescent nanoprobes (FNPs) have emerged as highly promising fluorescent probes for bioimaging due to their high brightness and excellent photostability. This paper focuses on the development and applications of FNPs as probes for live-cell super-resolution imaging. It provides an overview of different super-resolution methods, discusses the performance requirements for FNPs in these methods, and reviews the latest applications of FNPs in the super-resolution imaging of living cells. Finally, it addresses the challenges and future outlook in this field.展开更多
BACKGROUND Four-dimensional(4D)flow magnetic resonance imaging(MRI)is used as a noninvasive modality for assessing hemodynamic information with neurovascular and body applications.The application of 4D flow MRI for as...BACKGROUND Four-dimensional(4D)flow magnetic resonance imaging(MRI)is used as a noninvasive modality for assessing hemodynamic information with neurovascular and body applications.The application of 4D flow MRI for assessment of bowel disease in children has not been previously described.AIM To determine feasibility of superior mesenteric venous and arterial flow quantitation in pediatric patients using 4D flow MRI.METHODS Nine pediatric patients(7-14 years old,5 male and 4 female)with history or suspicion of bowel pathology,who underwent magnetic resonance(MR)enterography with 4D flow MR protocol from November 2022 to October 2023.Field strength/sequence:3T MRI using 4D flow MR protocol.Flow velocity and peak speed measurements were performed by two diagnostic radiologists placing the region of interest in perpendicular plane to blood flow on each cross section of superior mesenteric artery(SMA)and superior mesenteric vein(SMV)at three predetermined levels.Bland-Altman analysis,showed good agreement of flow velocity and peak speed measurements of SMV and SMA between two readers.RESULTS Mean SMV flow velocity increased from proximal to mid to distal(0.14 L/minute,0.17 L/minute,0.22 L/minute respectively).Mean SMA flow velocity decreased from proximal to mid to distal(0.35 L/minute,0.27 L/minute,0.21 L/minute respectively).Observed agreement was good for flow velocity measurements of SMV(mean bias-0.01 L/minute and 95%limits of agreement,-0.09 to 0.08 L/minute)and SMA(mean bias-0.03 L/minute and 95%limits of agreement,-0.23 to 0.17 L/minute)between two readers.Good agreement for peak speed measurements of SMV(mean bias-1.2 cm/second and 95%limits of agreement,-9.4 to 7.0 cm/second)and SMA(mean bias-3.2 cm/second and 95%limits of agreement,-31.4 to 24.9 cm/second).CONCLUSION Flow quantitation using 4D Flow is feasible to provide hemodynamic information for SMV and SMA in children.展开更多
Blood cells are the most integral part of the body,which are made up of erythrocytes,platelets and white blood cells.The examination of subcellular structures and proteins within blood cells at the nanoscale can provi...Blood cells are the most integral part of the body,which are made up of erythrocytes,platelets and white blood cells.The examination of subcellular structures and proteins within blood cells at the nanoscale can provide valuable insights into the health status of an individual,accurate diagnosis,and efficient treatment strategies for diseases.Super-resolution microscopy(SRM)has recently emerged as a cutting-edge tool for the study of blood cells,providing numerous advantages over traditional methods for examining subcellular structures and proteins.In this paper,we focus on outlining the fundamental principles of various SRM techniques and their applications in both normal and diseased states of blood cells.Furthermore,future prospects of SRM techniques in the analysis of blood cells are also discussed.展开更多
Visual assessment of tumor metastatic capacity is crucial for predicting hepatocellular carcinoma(HCC)prognosis and guiding clinical therapeutic approaches.In this study,we developed an enzyme-responsive probe based o...Visual assessment of tumor metastatic capacity is crucial for predicting hepatocellular carcinoma(HCC)prognosis and guiding clinical therapeutic approaches.In this study,we developed an enzyme-responsive probe based on the peptide GK10,which is selectively cleaved by matrix metalloproteinase-9(MMP-9),a critical marker for metastasis in HCC.The GK10 peptide was conjugated with near-infrared fiuorescent molecule IR783,fiuorescent quencher black hole quencher 3(BHQ3),and magnetic resonance(MR)contrast agent DOTA-Gd,forming the IR783-GK10-BHQ3-Gd probe.Upon MMP-9 cleavage of GK10,BHQ3 is released from the probe,thereby amplifying the previously quenched IR783 fiuorescence signal.In vitro experiments demonstrate the probe's impressive detection limit for MMP-9,as low as 1.84 ng/m L.Moreover,in vivo imaging results reveal that the probe can differentiate liver cancers with varying metastatic capacities.The fiuorescence and MR imaging signal intensity of high metastatic HCC are approximately1.2 times greater than that of low metastatic HCC.Thus,this engineered probe holds promise as a valuable tool for evaluating HCC metastatic capacity through fiuorescence-MR dual-mode imaging.展开更多
Honeycombing Lung(HCL)is a chronic lung condition marked by advanced fibrosis,resulting in enlarged air spaces with thick fibrotic walls,which are visible on Computed Tomography(CT)scans.Differentiating between normal...Honeycombing Lung(HCL)is a chronic lung condition marked by advanced fibrosis,resulting in enlarged air spaces with thick fibrotic walls,which are visible on Computed Tomography(CT)scans.Differentiating between normal lung tissue,honeycombing lungs,and Ground Glass Opacity(GGO)in CT images is often challenging for radiologists and may lead to misinterpretations.Although earlier studies have proposed models to detect and classify HCL,many faced limitations such as high computational demands,lower accuracy,and difficulty distinguishing between HCL and GGO.CT images are highly effective for lung classification due to their high resolution,3D visualization,and sensitivity to tissue density variations.This study introduces Honeycombing Lungs Network(HCL Net),a novel classification algorithm inspired by ResNet50V2 and enhanced to overcome the shortcomings of previous approaches.HCL Net incorporates additional residual blocks,refined preprocessing techniques,and selective parameter tuning to improve classification performance.The dataset,sourced from the University Malaya Medical Centre(UMMC)and verified by expert radiologists,consists of CT images of normal,honeycombing,and GGO lungs.Experimental evaluations across five assessments demonstrated that HCL Net achieved an outstanding classification accuracy of approximately 99.97%.It also recorded strong performance in other metrics,achieving 93%precision,100%sensitivity,89%specificity,and an AUC-ROC score of 97%.Comparative analysis with baseline feature engineering methods confirmed the superior efficacy of HCL Net.The model significantly reduces misclassification,particularly between honeycombing and GGO lungs,enhancing diagnostic precision and reliability in lung image analysis.展开更多
Modern manufacturing processes have become more reliant on automation because of the accelerated transition from Industry 3.0 to Industry 4.0.Manual inspection of products on assembly lines remains inefficient,prone t...Modern manufacturing processes have become more reliant on automation because of the accelerated transition from Industry 3.0 to Industry 4.0.Manual inspection of products on assembly lines remains inefficient,prone to errors and lacks consistency,emphasizing the need for a reliable and automated inspection system.Leveraging both object detection and image segmentation approaches,this research proposes a vision-based solution for the detection of various kinds of tools in the toolkit using deep learning(DL)models.Two Intel RealSense D455f depth cameras were arranged in a top down configuration to capture both RGB and depth images of the toolkits.After applying multiple constraints and enhancing them through preprocessing and augmentation,a dataset consisting of 3300 annotated RGB-D photos was generated.Several DL models were selected through a comprehensive assessment of mean Average Precision(mAP),precision-recall equilibrium,inference latency(target≥30 FPS),and computational burden,resulting in a preference for YOLO and Region-based Convolutional Neural Networks(R-CNN)variants over ViT-based models due to the latter’s increased latency and resource requirements.YOLOV5,YOLOV8,YOLOV11,Faster R-CNN,and Mask R-CNN were trained on the annotated dataset and evaluated using key performance metrics(Recall,Accuracy,F1-score,and Precision).YOLOV11 demonstrated balanced excellence with 93.0%precision,89.9%recall,and a 90.6%F1-score in object detection,as well as 96.9%precision,95.3%recall,and a 96.5%F1-score in instance segmentation with an average inference time of 25 ms per frame(≈40 FPS),demonstrating real-time performance.Leveraging these results,a YOLOV11-based windows application was successfully deployed in a real-time assembly line environment,where it accurately processed live video streams to detect and segment tools within toolkits,demonstrating its practical effectiveness in industrial automation.The application is capable of precisely measuring socket dimensions by utilising edge detection techniques on YOLOv11 segmentation masks,in addition to detection and segmentation.This makes it possible to do specification-level quality control right on the assembly line,which improves the ability to examine things in real time.The implementation is a big step forward for intelligent manufacturing in the Industry 4.0 paradigm.It provides a scalable,efficient,and accurate way to do automated inspection and dimensional verification activities.展开更多
Epilepsy is a leading cause of disability and mortality worldwide. However, despite the availability of more than 20 antiseizure medications, more than one-third of patients continue to experience seizures. Given the ...Epilepsy is a leading cause of disability and mortality worldwide. However, despite the availability of more than 20 antiseizure medications, more than one-third of patients continue to experience seizures. Given the urgent need to explore new treatment strategies for epilepsy, recent research has highlighted the potential of targeting gliosis, metabolic disturbances, and neural circuit abnormalities as therapeutic strategies. Astrocytes, the largest group of nonneuronal cells in the central nervous system, play several crucial roles in maintaining ionic and energy metabolic homeostasis in neurons, regulating neurotransmitter levels, and modulating synaptic plasticity. This article briefly reviews the critical role of astrocytes in maintaining balance within the central nervous system. Building on previous research, we discuss how astrocyte dysfunction contributes to the onset and progression of epilepsy through four key aspects: the imbalance between excitatory and inhibitory neuronal signaling, dysregulation of metabolic homeostasis in the neuronal microenvironment, neuroinflammation, and the formation of abnormal neural circuits. We summarize relevant basic research conducted over the past 5 years that has focused on modulating astrocytes as a therapeutic approach for epilepsy. We categorize the therapeutic targets proposed by these studies into four areas: restoration of the excitation–inhibition balance, reestablishment of metabolic homeostasis, modulation of immune and inflammatory responses, and reconstruction of abnormal neural circuits. These targets correspond to the pathophysiological mechanisms by which astrocytes contribute to epilepsy. Additionally, we need to consider the potential challenges and limitations of translating these identified therapeutic targets into clinical treatments. These limitations arise from interspecies differences between humans and animal models, as well as the complex comorbidities associated with epilepsy in humans. We also highlight valuable future research directions worth exploring in the treatment of epilepsy and the regulation of astrocytes, such as gene therapy and imaging strategies. The findings presented in this review may help open new therapeutic avenues for patients with drugresistant epilepsy and for those suffering from other central nervous system disorders associated with astrocytic dysfunction.展开更多
This study aims to investigate the responses of a perovskite-based direct-conversion dual-layer flat-panel detector(DL-FPD)numerically.To this end,the X-ray sensitivity,spatial resolution quantified by the modulation ...This study aims to investigate the responses of a perovskite-based direct-conversion dual-layer flat-panel detector(DL-FPD)numerically.To this end,the X-ray sensitivity,spatial resolution quantified by the modulation transfer function(MTF),and detective quantum efficiency(DQE)of the DL-FPD are evaluated numerically using a linear cascade model.In addition,both the single-crystal(SC)and polycrystalline(PC)structures of MAPbI_(3)are investigated,along with various other key parameters such as the material thickness,electric field strength,X-ray beam spectrum,and electronic readout noise.The results demonstrate that SC perovskite consistently exhibits better performance than PC perovskite owing to fewer material defects.Increasing the layer thickness may decrease the MTF,but can also enhance the sensitivity and DQE.Moreover,appropriately increasing the external electric field within the material can improve the sensitivity,MTF,and DQE.Finally,reducing the electronic readout noise can significantly enhance the DQE for low-dose imaging.This study demonstrates the potential of high-quality dual-energy X-ray imaging using direct-conversion perovskite DL-FPDs.展开更多
Understanding the acid resistance mechanism of S.mutans is crucial for preventing dental caries.FtsZ is the core protein for cell division in bacteria that can polymerize into Z-rings and drive cytokinesis.Our previou...Understanding the acid resistance mechanism of S.mutans is crucial for preventing dental caries.FtsZ is the core protein for cell division in bacteria that can polymerize into Z-rings and drive cytokinesis.Our previous study revealed that the FtsZ in S.mutans(SmFtsZ) has higher self-assembly and GTPase activity under acidic stress,which may be responsible for acid resistance and ca riogenesis of S.mutans.However,the functional structure mechanism of SmFtsZ under low pH conditions is still unclear.Here,we further reported the crystal structure of S.mutans FtsZ,revealing a unique lateral interface.Through protein polymerization and GTPase activity assay,we experimentally demonstrated that the mutation of Arg68 on this lateral interface significantly reduced the functional activity of FtsZ in an acidic environment.The phenotype assay and rat caries model further showed that the mutation of Arg68 effectively inhibited the acid resistance of S.mutans and the occurrence and progress of dental caries in vivo.By employing a molecular dynamics simulation analysis,we conclude that the mutation of Arg68 disrupts the conformation change necessary for SmFtsZ polymerization under acidic conditions.Our study proposes a novel mechanism to maintain FtsZ function in bacteria and could be a potential target for antimicrobial drugs to inhibit the growth of S.mutans in acidic environments.展开更多
Ultrasound neuromodulation shows promise for treating neurological disorders,but the underlying mechanisms remain unclear.Here,we developed an integrated surface acoustic wave(SAW)ultrasound chip enabling simultaneous...Ultrasound neuromodulation shows promise for treating neurological disorders,but the underlying mechanisms remain unclear.Here,we developed an integrated surface acoustic wave(SAW)ultrasound chip enabling simultaneous electrophysiological recording and Ca^(2+) imaging of cultured hippocampal neurons to investigate neuronal excitability and synaptic transmission during ultrasound stimulation.This study revealed,for the first time,three distinct neuronal response patterns induced by SAW ultrasound:an immediate response showing rapid activation,a delayed response exhibiting facilitation after several minutes,and a non-response maintaining baseline activity.Ultrasound stimulation increased action potential firing,enhanced excitatory postsynaptic currents,and elevated intracellular Ca^(2+) levels.These effects were dependent on extracellular Ca^(2+) influx and primarily dominated by L-type Ca^(2+) channels.Our findings suggest that individual neurons exhibit heterogeneous responses to SAW ultrasound stimulation based on their intracellular Ca^(2+) levels and L-type Ca^(2+) channel activity.This integrated approach provides new insights into the cellular mechanisms of ultrasound neuromodulation while highlighting the potential of SAW technology for precise,cell-type-specific neural control.展开更多
Radiology（imaging） and imaging-guided interventions, which provide multi-parametric morphologic and functional information, are playing an increasingly significant role in precision medicine. Radiologists are traine...Radiology（imaging） and imaging-guided interventions, which provide multi-parametric morphologic and functional information, are playing an increasingly significant role in precision medicine. Radiologists are trained to understand the imaging phenotypes, transcribe those observations（phenotypes） to correlate with underlying diseases and to characterize the images. However, in order to understand and characterize the molecular phenotype（to obtain genomic information） of solid heterogeneous tumours, the advanced sequencing of those tissues using biopsy is required. Thus, radiologists image the tissues from various views and angles in order to have the complete image phenotypes, thereby acquiring a huge amount of data. Deriving meaningful details from all these radiological data becomes challenging and raises the big data issues. Therefore, interest in the application of radiomics has been growing in recent years as it has the potential to provide significant interpretive and predictive information for decision support. Radiomics is a combination of conventional computer-aided diagnosis, deep learning methods, and human skills, and thus can be used for quantitative characterization of tumour phenotypes. This paper discusses the overview of radiomics workflow, the results of various radiomics-based studies conducted using various radiological images such as computed tomography（CT）, magnetic resonance imaging（MRI）, and positron-emission tomography（PET）, the challenges we are facing, and the potential contribution of radiomics towards precision medicine.展开更多
AIM:To elucidate the variety of ways early-stage hepatocellular carcinoma(HCC)can appear on magnetic resonance(MR)imaging by analyzing T1-weighted,T2-weighted,and gadolinium-enhanced dynamic studies.METHODS:Seventy-th...AIM:To elucidate the variety of ways early-stage hepatocellular carcinoma(HCC)can appear on magnetic resonance(MR)imaging by analyzing T1-weighted,T2-weighted,and gadolinium-enhanced dynamic studies.METHODS:Seventy-three patients with well-differentiated HCC(wHCC)or dysplastic nodules were retrospectively identified from medical records,and new histological sections were prepared and reviewed.The tumor nodules were categorized into three groups:dysplastic nodule(DN),wHCC compatible with Edmondson-Steiner grade I HCC(w1-HCC),and wHCC compatible with Edmondson-Steiner gradeⅡHCC(w2-HCC).The signal intensity on pre-contrast MR imaging and the enhancing pattern for each tumor were recorded and compared between the three tumor groups.RESULTS:Among the 73 patients,14 were diagnosed as having DN,40 were diagnosed as having w1-HCC,and 19 were diagnosed as having w2-HCC.Hyperintensity measurements on T2-weighted axial images(T2WI)were statistically significant between DNs and wHCC(P=0.006)and between DN and w1-HCC(P=0.02).The other imaging features revealed no significant differences between DN and wHCC or between DN and w1-HCC.Hyperintensity on both T1W out-phase imaging(P=0.007)and arterial enhancement on dynamic study(P=0.005)showed statistically significant differences between w1-HCC and w2-HCC.The other imaging features revealed no significant differences between w1-HCC and w2-HCC.CONCLUSION:In the follow-up for a cirrhotic nodule,increased signal intensity on T2WI may be a sign of malignant transformation.Furthermore,a noted loss of hyperintensity on T1WI and the detection of arterial enhancement might indicate further progression of the histological grade.展开更多
Dementia is a contemporary global health issue with far reaching consequences, not only for affected individuals and their families, but for national and global socio-economic conditions. The hallmark feature of demen...Dementia is a contemporary global health issue with far reaching consequences, not only for affected individuals and their families, but for national and global socio-economic conditions. The hallmark feature of dementia is that of irreversible cognitive decline, usually affecting memory, and impaired activities of daily living. Advances in healthcare worldwide have facilitated longer life spans, increasing the risks of developing cognitive decline and dementia in late life. Dementia remains a clinical diagnosis. The role of structural and molecular neuroimaging in patients with dementia is primarily supportive role rather than diagnostic, American and European guidelines recommending imaging to exclude treatable causes of dementia, such as tumor, hydrocephalus or intracranial haemorrhage, but also to distinguish between different dementia subtypes, the commonest of which is Alzheimer’s disease. However, this depends on the availability of these imaging techniques at individual centres. Advanced magnetic resonance imaging (MRI) techniques, such as functional connectivity MRI, diffusion tensor imaging and magnetic resonance spectroscopy, and molecular imaging techniques, such as 18F fluoro-deoxy glucose positron emission tomography (PET), amyloid PET, tau PET, are currently within the realm of dementia research but are available for clinical use. Increasingly the research focus is on earlier identification of at risk preclinical individuals, for example due to family history. Intervention at the preclinical stages before irreversible brain damage occurs is currently the best hope of reducing the impact of dementia.展开更多
Multiple sclerosis(MS) is a disease of the central nervous system characterized by inflammation, demyelination, and neuronal damage. Environmental and genetic factors are associated with the risk of developing MS, but...Multiple sclerosis(MS) is a disease of the central nervous system characterized by inflammation, demyelination, and neuronal damage. Environmental and genetic factors are associated with the risk of developing MS, but the exact cause still remains unidentified. Epstein-Barr virus(EBV), vitamin D, and smoking are among the most well-established environmental risk factors in MS. Infectious mononucleosis, which is caused by delayed primary EBV infection, increases the risk of developing MS. EBV may also contribute to MS pathogenesis indirectly by activating silent human endogenous retrovirus-W. The emerging B-cell depleting therapies, particularly anti-CD20 agents such as rituximab, ocrelizumab, as well as the fully human ofatumumab, have shown promising clinical and magnetic resonance imaging benefit. One potential effect of these therapies is the depletion of memory B-cells, the primary reservoir site where EBV latency occurs. In addition, EBV potentially interacts with both genetic and other environmental factors to increase susceptibility and disease severity of MS. This review examines the role of EBV in MS pathophysiology and summarizes the recent clinical and radiological findings, with a focus on B-cells and in vivo imaging. Addressing the potential link between EBV and MS allows the better understanding of MS pathogenesis and helps to identify additional disease biomarkers that may be responsive to B-cell depleting intervention.展开更多
Objective To determine the association between the irregularity of carotid plaque surface using multidimensional magnetic resonance imaging(MRI) of ipsilateral acute cerebral infarction(ACI) cases. Methods Patients wi...Objective To determine the association between the irregularity of carotid plaque surface using multidimensional magnetic resonance imaging(MRI) of ipsilateral acute cerebral infarction(ACI) cases. Methods Patients with recent cerebrovascular symptoms(stroke or transient ischemic attack < 2 weeks) and atherosclerotic plaque in at least one carotid artery were diagnosed by B-mode ultrasound imaging(intima-media thickness ≥ 1.5 mm) and recruited for the present study. Irregular surface was defined when plaque surface was uneven with high and low fluctuation or plaque with surface ulceration. The irregularity of carotid plaque surface was determined on axial or oblique images alone(single-dimension) and on both axial images and oblique images(multidimensions), separately. Univariate and multivariate logistic regression analyses were performed to calculate the odds ratio(OR) and the corresponding 95% CI of the irregular plaque surface in discriminating the presence of ipsilateral ACI. Results A total of 217 included subjects(mean age: 60.7 ± 10.2 years, 149 men) were recruited and 89(41.0%), 88(40.6%) and 118(54.4%) of them exhibited irregular plaque surface on axial, oblique and multidimensional MR images, respectively. The OR of irregularity of the plaque surface was determined by multidimensional MRI to be 5.88(95% CI: 3.16–10.96, P < 0.001) in discriminating the presence of ipsilateral ACI. Following adjustment for clinical confounding factors, this association remained statistically significant(OR = 5.65, 95% CI: 2.53–12.60, P < 0.001). The analysis included further adjustment for the presence of lipid-rich necrotic core, intraplaque hemorrhage and stenosis and the results included that this association also remained statistically significant(OR = 6.08, 95% CI: 2.52–14.68, P < 0.001). Conclusions The irregular plaque surface was determined by multidimensional MRI as an independent indicator for ipsilateral acute cerebral infarction.展开更多
Magnetic resonance imaging(MRI) is highly sensitive in identifying residual breast cancer following neoadjuvant chemotherapy(NAC), and consequently is a commonly used imaging modality in locally advanced breast cancer...Magnetic resonance imaging(MRI) is highly sensitive in identifying residual breast cancer following neoadjuvant chemotherapy(NAC), and consequently is a commonly used imaging modality in locally advanced breast cancer patients. In these patients, tumor response is an important prognostic indicator. However, discrepancies between MRI findings and surgical pathology are well documented. Overestimation of residual disease by MRI may result in greater surgery than is actually required while underestimation may result in insufficient surgery. Thus, it is important to understand when MRI findings are reliable and when they are less accurate. MRI most accurately predicts pathology in triple negative, Her2 positive and hormone receptor negative tumors, especially if they are of a solid imaging phenotype. In these cases, post-NAC MRI is highly reliable for surgical planning. Hormone receptor positive cancers and those demonstrating non mass enhancement show lower concordance with surgical pathology, making surgical guidance more nebulous in these cases. Radiologists and surgeons must assess MRI response to NAC in the context of tumor subtype. Indiscriminate interpretations will prevent MRI from achieving its maximum potential in the pre-operative setting.展开更多
Myocardial pathologies are major causes of morbidity and mortality worldwide. Early detection of loss of cellular integrity and expansion in extracellular volume(ECV) in myocardium is critical to initiate effective tr...Myocardial pathologies are major causes of morbidity and mortality worldwide. Early detection of loss of cellular integrity and expansion in extracellular volume(ECV) in myocardium is critical to initiate effective treatment. The three compartments in healthy myocardium are: intravascular(approximately 10% of tissue volume), interstitium(approximately 15%) and intracellular(approximately 75%). Myocardial cells, fibroblasts and vascular endothelial/smooth muscle cells represent intracellular compartment and the main proteins in the interstitium are types Ⅰ/Ⅲ collagens. Microscopic studies have shown that expansion of ECV is an important feature of diffuse physiologic fibrosis(e.g., aging and obesity) and pathologic fibrosis [heart failure, aortic valve disease, hypertrophic cardiomyopathy, myocarditis, dilated cardiomyopathy, amyloidosis, congenital heart disease, aortic stenosis, restrictive cardiomyopathy(hypereosinophilic and idiopathic types), arrythmogenic right ventricular dysplasia and hypertension]. This review addresses recent advances in measuring of ECV in ischemic and non-ischemic myocardial pathologies. Magnetic resonance imaging(MRI) has the ability to characterize tissue proton relaxation times(T1, T2, and T2*). Proton relaxation times reflect the physical and chemical environments of water protons in myocardium. Delayed contrast enhanced-MRI(DE-MRI) and multi-detector computed tomography(DE-MDCT) demonstrated hyper-enhanced infarct, hypo-enhanced microvascular obstruction zone and moderately enhanced peri-infarct zone, but are limited for visualizing diffuse fibrosis and patchy microinfarct despite the increase in ECV. ECV can be measured on equilibrium contrast enhanced MRI/MDCT and MRI longitudinal relaxation time mapping. Equilibrium contrast enhanced MRI/MDCT and MRI T1 mapping is currently used, but at a lower scale, as an alternative to invasive sub-endomyocardial biopsies to eliminate the need for anesthesia, coronary catheterization and possibility of tissue sampling error. Similar to delayed contrast enhancement, equilibrium contrast enhanced MRI/MDCT and T1 mapping is completely noninvasive and may play a specialized role in diagnosis of subclinical and other myocardial pathologies. DE-MRI and when T1-mapping demonstrated sub-epicardium, sub-endocardial and patchy mid-myocardial enhancement in myocarditis, Behcet's disease and sarcoidosis, respectively. Furthermore, recent studies showed that the combined technique of cine, T2-weighted and DE-MRI technique has high diagnostic accuracy for detecting myocarditis. When the tomographic techniques are coupled with myocardial perfusion and left ventricular function they can provide valuable information on the progression of myocardial pathologies and effectiveness of new therapies.展开更多
文摘The field of biomedical imaging has been revolutionized by deep learning techniques.This special issue is focused on the theme of“AI-based Image Analysis”.Because there are so many conferences and journals in this field,our special issue can only be a small snapshot of a much bigger and highly dynamic picture.In this special issue,we present six papers that highlight the power of deep learning in solving challenging biomedical imaging and image analysis problems.
基金supported by the National Key Research and Development Program of China(2022YFC3401100,2024YFC3406402,and 2024YFF0507400)the National Natural Science Foundation of China(62371007 and 6220071694)the Beijing Natural Science Foundation(Z240010).
文摘Computational biomedical imaging lies at the intersection of physics,computer science,and biomedicine,aiming to produce visual representations of biological or physiological phenomena that may be otherwise imperceptible to measuring instruments.Over the last few decades,breakthroughs in imaging physics-as evidenced by modalities like magnetic resonance imaging(MRI),computed tomography(CT),ultrasound,optical microscopy,and endoscopy-have profoundly impacted the way clinicians visualize and understand living systems.
文摘Perface In his 1790 book,The Critique of Judgment,Immanuel Kant asserted that“Life is a self-organized and self-producing process,and the existence and form of its parts are only possible through their relation to the whole…”.However,such a holistic and complex perspective is challenging to separate and study objectively.
基金supported by the following grants:National Natural Science Foundation of China(grant nos.92354305,32271428,and 32201132)National Key R&D Program of China(grant no.2022YFC3401100)+1 种基金Fund for Knowledge Innovation of Wuhan Science and Technology Bureau(grant no.2022020801010558)Director Fund of WNLO.
文摘The rapid development of super-resolution microscopy has made it possible to observe subcellular structures and dynamic behaviors in living cells with nanoscale spatial resolution, greatly advancing progress in life sciences. As hardware technology continues to evolve, the availability of new fluorescent probes with superior performance is becoming increasingly important. In recent years, fluorescent nanoprobes (FNPs) have emerged as highly promising fluorescent probes for bioimaging due to their high brightness and excellent photostability. This paper focuses on the development and applications of FNPs as probes for live-cell super-resolution imaging. It provides an overview of different super-resolution methods, discusses the performance requirements for FNPs in these methods, and reviews the latest applications of FNPs in the super-resolution imaging of living cells. Finally, it addresses the challenges and future outlook in this field.
文摘BACKGROUND Four-dimensional(4D)flow magnetic resonance imaging(MRI)is used as a noninvasive modality for assessing hemodynamic information with neurovascular and body applications.The application of 4D flow MRI for assessment of bowel disease in children has not been previously described.AIM To determine feasibility of superior mesenteric venous and arterial flow quantitation in pediatric patients using 4D flow MRI.METHODS Nine pediatric patients(7-14 years old,5 male and 4 female)with history or suspicion of bowel pathology,who underwent magnetic resonance(MR)enterography with 4D flow MR protocol from November 2022 to October 2023.Field strength/sequence:3T MRI using 4D flow MR protocol.Flow velocity and peak speed measurements were performed by two diagnostic radiologists placing the region of interest in perpendicular plane to blood flow on each cross section of superior mesenteric artery(SMA)and superior mesenteric vein(SMV)at three predetermined levels.Bland-Altman analysis,showed good agreement of flow velocity and peak speed measurements of SMV and SMA between two readers.RESULTS Mean SMV flow velocity increased from proximal to mid to distal(0.14 L/minute,0.17 L/minute,0.22 L/minute respectively).Mean SMA flow velocity decreased from proximal to mid to distal(0.35 L/minute,0.27 L/minute,0.21 L/minute respectively).Observed agreement was good for flow velocity measurements of SMV(mean bias-0.01 L/minute and 95%limits of agreement,-0.09 to 0.08 L/minute)and SMA(mean bias-0.03 L/minute and 95%limits of agreement,-0.23 to 0.17 L/minute)between two readers.Good agreement for peak speed measurements of SMV(mean bias-1.2 cm/second and 95%limits of agreement,-9.4 to 7.0 cm/second)and SMA(mean bias-3.2 cm/second and 95%limits of agreement,-31.4 to 24.9 cm/second).CONCLUSION Flow quantitation using 4D Flow is feasible to provide hemodynamic information for SMV and SMA in children.
基金supported by the following grants:National Key R&D Program of China(Grant no.2022YFC3401100)National Natural Science Foundation of China(Grant nos.32271428,92054110,32201132 and 31600692).
文摘Blood cells are the most integral part of the body,which are made up of erythrocytes,platelets and white blood cells.The examination of subcellular structures and proteins within blood cells at the nanoscale can provide valuable insights into the health status of an individual,accurate diagnosis,and efficient treatment strategies for diseases.Super-resolution microscopy(SRM)has recently emerged as a cutting-edge tool for the study of blood cells,providing numerous advantages over traditional methods for examining subcellular structures and proteins.In this paper,we focus on outlining the fundamental principles of various SRM techniques and their applications in both normal and diseased states of blood cells.Furthermore,future prospects of SRM techniques in the analysis of blood cells are also discussed.
基金financially supported by the National Natural Science Foundation of China(Nos.32025021,31971292,32111540257)the Zhejiang Province Financial Supporting(Nos.2020C03110 and 2023C04017)the Key Scientific and Technological Special Project of Ningbo City(No.2020Z094)。
文摘Visual assessment of tumor metastatic capacity is crucial for predicting hepatocellular carcinoma(HCC)prognosis and guiding clinical therapeutic approaches.In this study,we developed an enzyme-responsive probe based on the peptide GK10,which is selectively cleaved by matrix metalloproteinase-9(MMP-9),a critical marker for metastasis in HCC.The GK10 peptide was conjugated with near-infrared fiuorescent molecule IR783,fiuorescent quencher black hole quencher 3(BHQ3),and magnetic resonance(MR)contrast agent DOTA-Gd,forming the IR783-GK10-BHQ3-Gd probe.Upon MMP-9 cleavage of GK10,BHQ3 is released from the probe,thereby amplifying the previously quenched IR783 fiuorescence signal.In vitro experiments demonstrate the probe's impressive detection limit for MMP-9,as low as 1.84 ng/m L.Moreover,in vivo imaging results reveal that the probe can differentiate liver cancers with varying metastatic capacities.The fiuorescence and MR imaging signal intensity of high metastatic HCC are approximately1.2 times greater than that of low metastatic HCC.Thus,this engineered probe holds promise as a valuable tool for evaluating HCC metastatic capacity through fiuorescence-MR dual-mode imaging.
文摘Honeycombing Lung(HCL)is a chronic lung condition marked by advanced fibrosis,resulting in enlarged air spaces with thick fibrotic walls,which are visible on Computed Tomography(CT)scans.Differentiating between normal lung tissue,honeycombing lungs,and Ground Glass Opacity(GGO)in CT images is often challenging for radiologists and may lead to misinterpretations.Although earlier studies have proposed models to detect and classify HCL,many faced limitations such as high computational demands,lower accuracy,and difficulty distinguishing between HCL and GGO.CT images are highly effective for lung classification due to their high resolution,3D visualization,and sensitivity to tissue density variations.This study introduces Honeycombing Lungs Network(HCL Net),a novel classification algorithm inspired by ResNet50V2 and enhanced to overcome the shortcomings of previous approaches.HCL Net incorporates additional residual blocks,refined preprocessing techniques,and selective parameter tuning to improve classification performance.The dataset,sourced from the University Malaya Medical Centre(UMMC)and verified by expert radiologists,consists of CT images of normal,honeycombing,and GGO lungs.Experimental evaluations across five assessments demonstrated that HCL Net achieved an outstanding classification accuracy of approximately 99.97%.It also recorded strong performance in other metrics,achieving 93%precision,100%sensitivity,89%specificity,and an AUC-ROC score of 97%.Comparative analysis with baseline feature engineering methods confirmed the superior efficacy of HCL Net.The model significantly reduces misclassification,particularly between honeycombing and GGO lungs,enhancing diagnostic precision and reliability in lung image analysis.
文摘Modern manufacturing processes have become more reliant on automation because of the accelerated transition from Industry 3.0 to Industry 4.0.Manual inspection of products on assembly lines remains inefficient,prone to errors and lacks consistency,emphasizing the need for a reliable and automated inspection system.Leveraging both object detection and image segmentation approaches,this research proposes a vision-based solution for the detection of various kinds of tools in the toolkit using deep learning(DL)models.Two Intel RealSense D455f depth cameras were arranged in a top down configuration to capture both RGB and depth images of the toolkits.After applying multiple constraints and enhancing them through preprocessing and augmentation,a dataset consisting of 3300 annotated RGB-D photos was generated.Several DL models were selected through a comprehensive assessment of mean Average Precision(mAP),precision-recall equilibrium,inference latency(target≥30 FPS),and computational burden,resulting in a preference for YOLO and Region-based Convolutional Neural Networks(R-CNN)variants over ViT-based models due to the latter’s increased latency and resource requirements.YOLOV5,YOLOV8,YOLOV11,Faster R-CNN,and Mask R-CNN were trained on the annotated dataset and evaluated using key performance metrics(Recall,Accuracy,F1-score,and Precision).YOLOV11 demonstrated balanced excellence with 93.0%precision,89.9%recall,and a 90.6%F1-score in object detection,as well as 96.9%precision,95.3%recall,and a 96.5%F1-score in instance segmentation with an average inference time of 25 ms per frame(≈40 FPS),demonstrating real-time performance.Leveraging these results,a YOLOV11-based windows application was successfully deployed in a real-time assembly line environment,where it accurately processed live video streams to detect and segment tools within toolkits,demonstrating its practical effectiveness in industrial automation.The application is capable of precisely measuring socket dimensions by utilising edge detection techniques on YOLOv11 segmentation masks,in addition to detection and segmentation.This makes it possible to do specification-level quality control right on the assembly line,which improves the ability to examine things in real time.The implementation is a big step forward for intelligent manufacturing in the Industry 4.0 paradigm.It provides a scalable,efficient,and accurate way to do automated inspection and dimensional verification activities.
基金supported by the National Key Research and Development Program of China,No. 2023YFF0714200 (to CW)the National Natural Science Foundation of China,Nos. 82472038 and 82202224 (both to CW)+3 种基金the Shanghai Rising-Star Program,No. 23QA1407700 (to CW)the Construction Project of Shanghai Key Laboratory of Molecular Imaging,No. 18DZ2260400 (to CW)the National Science Foundation for Distinguished Young Scholars,No. 82025019 (to CL)the Greater Bay Area Institute of Precision Medicine (Guangzhou)(to CW)。
文摘Epilepsy is a leading cause of disability and mortality worldwide. However, despite the availability of more than 20 antiseizure medications, more than one-third of patients continue to experience seizures. Given the urgent need to explore new treatment strategies for epilepsy, recent research has highlighted the potential of targeting gliosis, metabolic disturbances, and neural circuit abnormalities as therapeutic strategies. Astrocytes, the largest group of nonneuronal cells in the central nervous system, play several crucial roles in maintaining ionic and energy metabolic homeostasis in neurons, regulating neurotransmitter levels, and modulating synaptic plasticity. This article briefly reviews the critical role of astrocytes in maintaining balance within the central nervous system. Building on previous research, we discuss how astrocyte dysfunction contributes to the onset and progression of epilepsy through four key aspects: the imbalance between excitatory and inhibitory neuronal signaling, dysregulation of metabolic homeostasis in the neuronal microenvironment, neuroinflammation, and the formation of abnormal neural circuits. We summarize relevant basic research conducted over the past 5 years that has focused on modulating astrocytes as a therapeutic approach for epilepsy. We categorize the therapeutic targets proposed by these studies into four areas: restoration of the excitation–inhibition balance, reestablishment of metabolic homeostasis, modulation of immune and inflammatory responses, and reconstruction of abnormal neural circuits. These targets correspond to the pathophysiological mechanisms by which astrocytes contribute to epilepsy. Additionally, we need to consider the potential challenges and limitations of translating these identified therapeutic targets into clinical treatments. These limitations arise from interspecies differences between humans and animal models, as well as the complex comorbidities associated with epilepsy in humans. We also highlight valuable future research directions worth exploring in the treatment of epilepsy and the regulation of astrocytes, such as gene therapy and imaging strategies. The findings presented in this review may help open new therapeutic avenues for patients with drugresistant epilepsy and for those suffering from other central nervous system disorders associated with astrocytic dysfunction.
基金supported in part by the National Natural Science Foundation of China(Nos.12305349,12235006,12027812)Shenzhen Science and Technology Program(No.JSGGKQTD20210831174329010)Guangdong Basic and Applied Basic Research Foundation(No.2021TQ06Y108).
文摘This study aims to investigate the responses of a perovskite-based direct-conversion dual-layer flat-panel detector(DL-FPD)numerically.To this end,the X-ray sensitivity,spatial resolution quantified by the modulation transfer function(MTF),and detective quantum efficiency(DQE)of the DL-FPD are evaluated numerically using a linear cascade model.In addition,both the single-crystal(SC)and polycrystalline(PC)structures of MAPbI_(3)are investigated,along with various other key parameters such as the material thickness,electric field strength,X-ray beam spectrum,and electronic readout noise.The results demonstrate that SC perovskite consistently exhibits better performance than PC perovskite owing to fewer material defects.Increasing the layer thickness may decrease the MTF,but can also enhance the sensitivity and DQE.Moreover,appropriately increasing the external electric field within the material can improve the sensitivity,MTF,and DQE.Finally,reducing the electronic readout noise can significantly enhance the DQE for low-dose imaging.This study demonstrates the potential of high-quality dual-energy X-ray imaging using direct-conversion perovskite DL-FPDs.
基金supported by the Beijing Natural Science Foundation:7222220National Natural Science Foundation of China (82001039)+2 种基金Research Foundation of Peking University School and Hospital of Stomatology:PKUSS20230117The Fundamental Research Funds for the Central UniversitiesYoung Elite Scientist Sponsorship Program by CAST (No.2019QNRC001 to Y.L.L)。
文摘Understanding the acid resistance mechanism of S.mutans is crucial for preventing dental caries.FtsZ is the core protein for cell division in bacteria that can polymerize into Z-rings and drive cytokinesis.Our previous study revealed that the FtsZ in S.mutans(SmFtsZ) has higher self-assembly and GTPase activity under acidic stress,which may be responsible for acid resistance and ca riogenesis of S.mutans.However,the functional structure mechanism of SmFtsZ under low pH conditions is still unclear.Here,we further reported the crystal structure of S.mutans FtsZ,revealing a unique lateral interface.Through protein polymerization and GTPase activity assay,we experimentally demonstrated that the mutation of Arg68 on this lateral interface significantly reduced the functional activity of FtsZ in an acidic environment.The phenotype assay and rat caries model further showed that the mutation of Arg68 effectively inhibited the acid resistance of S.mutans and the occurrence and progress of dental caries in vivo.By employing a molecular dynamics simulation analysis,we conclude that the mutation of Arg68 disrupts the conformation change necessary for SmFtsZ polymerization under acidic conditions.Our study proposes a novel mechanism to maintain FtsZ function in bacteria and could be a potential target for antimicrobial drugs to inhibit the growth of S.mutans in acidic environments.
基金supported by the National Key Research&Development Program of China(2022YFC3602700,2022YFC3602702)the Science and Technology Innovation 2030-Brain Science and Brain-Inspired Intelligence Project(2021ZD0201301)+2 种基金the National Natural Science Foundation of China(12034015,62088101,32170688,323B1004)Program of Shanghai Academic Research Leader(21XD1403600)Shanghai Municipal Science and Technology Major Project(2021SHZDZX0100,2018SHZDZX01).
文摘Ultrasound neuromodulation shows promise for treating neurological disorders,but the underlying mechanisms remain unclear.Here,we developed an integrated surface acoustic wave(SAW)ultrasound chip enabling simultaneous electrophysiological recording and Ca^(2+) imaging of cultured hippocampal neurons to investigate neuronal excitability and synaptic transmission during ultrasound stimulation.This study revealed,for the first time,three distinct neuronal response patterns induced by SAW ultrasound:an immediate response showing rapid activation,a delayed response exhibiting facilitation after several minutes,and a non-response maintaining baseline activity.Ultrasound stimulation increased action potential firing,enhanced excitatory postsynaptic currents,and elevated intracellular Ca^(2+) levels.These effects were dependent on extracellular Ca^(2+) influx and primarily dominated by L-type Ca^(2+) channels.Our findings suggest that individual neurons exhibit heterogeneous responses to SAW ultrasound stimulation based on their intracellular Ca^(2+) levels and L-type Ca^(2+) channel activity.This integrated approach provides new insights into the cellular mechanisms of ultrasound neuromodulation while highlighting the potential of SAW technology for precise,cell-type-specific neural control.
文摘Radiology（imaging） and imaging-guided interventions, which provide multi-parametric morphologic and functional information, are playing an increasingly significant role in precision medicine. Radiologists are trained to understand the imaging phenotypes, transcribe those observations（phenotypes） to correlate with underlying diseases and to characterize the images. However, in order to understand and characterize the molecular phenotype（to obtain genomic information） of solid heterogeneous tumours, the advanced sequencing of those tissues using biopsy is required. Thus, radiologists image the tissues from various views and angles in order to have the complete image phenotypes, thereby acquiring a huge amount of data. Deriving meaningful details from all these radiological data becomes challenging and raises the big data issues. Therefore, interest in the application of radiomics has been growing in recent years as it has the potential to provide significant interpretive and predictive information for decision support. Radiomics is a combination of conventional computer-aided diagnosis, deep learning methods, and human skills, and thus can be used for quantitative characterization of tumour phenotypes. This paper discusses the overview of radiomics workflow, the results of various radiomics-based studies conducted using various radiological images such as computed tomography（CT）, magnetic resonance imaging（MRI）, and positron-emission tomography（PET）, the challenges we are facing, and the potential contribution of radiomics towards precision medicine.
文摘AIM:To elucidate the variety of ways early-stage hepatocellular carcinoma(HCC)can appear on magnetic resonance(MR)imaging by analyzing T1-weighted,T2-weighted,and gadolinium-enhanced dynamic studies.METHODS:Seventy-three patients with well-differentiated HCC(wHCC)or dysplastic nodules were retrospectively identified from medical records,and new histological sections were prepared and reviewed.The tumor nodules were categorized into three groups:dysplastic nodule(DN),wHCC compatible with Edmondson-Steiner grade I HCC(w1-HCC),and wHCC compatible with Edmondson-Steiner gradeⅡHCC(w2-HCC).The signal intensity on pre-contrast MR imaging and the enhancing pattern for each tumor were recorded and compared between the three tumor groups.RESULTS:Among the 73 patients,14 were diagnosed as having DN,40 were diagnosed as having w1-HCC,and 19 were diagnosed as having w2-HCC.Hyperintensity measurements on T2-weighted axial images(T2WI)were statistically significant between DNs and wHCC(P=0.006)and between DN and w1-HCC(P=0.02).The other imaging features revealed no significant differences between DN and wHCC or between DN and w1-HCC.Hyperintensity on both T1W out-phase imaging(P=0.007)and arterial enhancement on dynamic study(P=0.005)showed statistically significant differences between w1-HCC and w2-HCC.The other imaging features revealed no significant differences between w1-HCC and w2-HCC.CONCLUSION:In the follow-up for a cirrhotic nodule,increased signal intensity on T2WI may be a sign of malignant transformation.Furthermore,a noted loss of hyperintensity on T1WI and the detection of arterial enhancement might indicate further progression of the histological grade.
文摘Dementia is a contemporary global health issue with far reaching consequences, not only for affected individuals and their families, but for national and global socio-economic conditions. The hallmark feature of dementia is that of irreversible cognitive decline, usually affecting memory, and impaired activities of daily living. Advances in healthcare worldwide have facilitated longer life spans, increasing the risks of developing cognitive decline and dementia in late life. Dementia remains a clinical diagnosis. The role of structural and molecular neuroimaging in patients with dementia is primarily supportive role rather than diagnostic, American and European guidelines recommending imaging to exclude treatable causes of dementia, such as tumor, hydrocephalus or intracranial haemorrhage, but also to distinguish between different dementia subtypes, the commonest of which is Alzheimer’s disease. However, this depends on the availability of these imaging techniques at individual centres. Advanced magnetic resonance imaging (MRI) techniques, such as functional connectivity MRI, diffusion tensor imaging and magnetic resonance spectroscopy, and molecular imaging techniques, such as 18F fluoro-deoxy glucose positron emission tomography (PET), amyloid PET, tau PET, are currently within the realm of dementia research but are available for clinical use. Increasingly the research focus is on earlier identification of at risk preclinical individuals, for example due to family history. Intervention at the preclinical stages before irreversible brain damage occurs is currently the best hope of reducing the impact of dementia.
文摘Multiple sclerosis(MS) is a disease of the central nervous system characterized by inflammation, demyelination, and neuronal damage. Environmental and genetic factors are associated with the risk of developing MS, but the exact cause still remains unidentified. Epstein-Barr virus(EBV), vitamin D, and smoking are among the most well-established environmental risk factors in MS. Infectious mononucleosis, which is caused by delayed primary EBV infection, increases the risk of developing MS. EBV may also contribute to MS pathogenesis indirectly by activating silent human endogenous retrovirus-W. The emerging B-cell depleting therapies, particularly anti-CD20 agents such as rituximab, ocrelizumab, as well as the fully human ofatumumab, have shown promising clinical and magnetic resonance imaging benefit. One potential effect of these therapies is the depletion of memory B-cells, the primary reservoir site where EBV latency occurs. In addition, EBV potentially interacts with both genetic and other environmental factors to increase susceptibility and disease severity of MS. This review examines the role of EBV in MS pathophysiology and summarizes the recent clinical and radiological findings, with a focus on B-cells and in vivo imaging. Addressing the potential link between EBV and MS allows the better understanding of MS pathogenesis and helps to identify additional disease biomarkers that may be responsive to B-cell depleting intervention.
基金supported by the National Natural Science Foundation of China (No. 81771825)Beijing Municipal Science and Technology Commission (D1711000 03017003)Ministry of Science and Technology of China (2017YFC1307904)
文摘Objective To determine the association between the irregularity of carotid plaque surface using multidimensional magnetic resonance imaging(MRI) of ipsilateral acute cerebral infarction(ACI) cases. Methods Patients with recent cerebrovascular symptoms(stroke or transient ischemic attack < 2 weeks) and atherosclerotic plaque in at least one carotid artery were diagnosed by B-mode ultrasound imaging(intima-media thickness ≥ 1.5 mm) and recruited for the present study. Irregular surface was defined when plaque surface was uneven with high and low fluctuation or plaque with surface ulceration. The irregularity of carotid plaque surface was determined on axial or oblique images alone(single-dimension) and on both axial images and oblique images(multidimensions), separately. Univariate and multivariate logistic regression analyses were performed to calculate the odds ratio(OR) and the corresponding 95% CI of the irregular plaque surface in discriminating the presence of ipsilateral ACI. Results A total of 217 included subjects(mean age: 60.7 ± 10.2 years, 149 men) were recruited and 89(41.0%), 88(40.6%) and 118(54.4%) of them exhibited irregular plaque surface on axial, oblique and multidimensional MR images, respectively. The OR of irregularity of the plaque surface was determined by multidimensional MRI to be 5.88(95% CI: 3.16–10.96, P < 0.001) in discriminating the presence of ipsilateral ACI. Following adjustment for clinical confounding factors, this association remained statistically significant(OR = 5.65, 95% CI: 2.53–12.60, P < 0.001). The analysis included further adjustment for the presence of lipid-rich necrotic core, intraplaque hemorrhage and stenosis and the results included that this association also remained statistically significant(OR = 6.08, 95% CI: 2.52–14.68, P < 0.001). Conclusions The irregular plaque surface was determined by multidimensional MRI as an independent indicator for ipsilateral acute cerebral infarction.
文摘Magnetic resonance imaging(MRI) is highly sensitive in identifying residual breast cancer following neoadjuvant chemotherapy(NAC), and consequently is a commonly used imaging modality in locally advanced breast cancer patients. In these patients, tumor response is an important prognostic indicator. However, discrepancies between MRI findings and surgical pathology are well documented. Overestimation of residual disease by MRI may result in greater surgery than is actually required while underestimation may result in insufficient surgery. Thus, it is important to understand when MRI findings are reliable and when they are less accurate. MRI most accurately predicts pathology in triple negative, Her2 positive and hormone receptor negative tumors, especially if they are of a solid imaging phenotype. In these cases, post-NAC MRI is highly reliable for surgical planning. Hormone receptor positive cancers and those demonstrating non mass enhancement show lower concordance with surgical pathology, making surgical guidance more nebulous in these cases. Radiologists and surgeons must assess MRI response to NAC in the context of tumor subtype. Indiscriminate interpretations will prevent MRI from achieving its maximum potential in the pre-operative setting.
文摘Myocardial pathologies are major causes of morbidity and mortality worldwide. Early detection of loss of cellular integrity and expansion in extracellular volume(ECV) in myocardium is critical to initiate effective treatment. The three compartments in healthy myocardium are: intravascular(approximately 10% of tissue volume), interstitium(approximately 15%) and intracellular(approximately 75%). Myocardial cells, fibroblasts and vascular endothelial/smooth muscle cells represent intracellular compartment and the main proteins in the interstitium are types Ⅰ/Ⅲ collagens. Microscopic studies have shown that expansion of ECV is an important feature of diffuse physiologic fibrosis(e.g., aging and obesity) and pathologic fibrosis [heart failure, aortic valve disease, hypertrophic cardiomyopathy, myocarditis, dilated cardiomyopathy, amyloidosis, congenital heart disease, aortic stenosis, restrictive cardiomyopathy(hypereosinophilic and idiopathic types), arrythmogenic right ventricular dysplasia and hypertension]. This review addresses recent advances in measuring of ECV in ischemic and non-ischemic myocardial pathologies. Magnetic resonance imaging(MRI) has the ability to characterize tissue proton relaxation times(T1, T2, and T2*). Proton relaxation times reflect the physical and chemical environments of water protons in myocardium. Delayed contrast enhanced-MRI(DE-MRI) and multi-detector computed tomography(DE-MDCT) demonstrated hyper-enhanced infarct, hypo-enhanced microvascular obstruction zone and moderately enhanced peri-infarct zone, but are limited for visualizing diffuse fibrosis and patchy microinfarct despite the increase in ECV. ECV can be measured on equilibrium contrast enhanced MRI/MDCT and MRI longitudinal relaxation time mapping. Equilibrium contrast enhanced MRI/MDCT and MRI T1 mapping is currently used, but at a lower scale, as an alternative to invasive sub-endomyocardial biopsies to eliminate the need for anesthesia, coronary catheterization and possibility of tissue sampling error. Similar to delayed contrast enhancement, equilibrium contrast enhanced MRI/MDCT and T1 mapping is completely noninvasive and may play a specialized role in diagnosis of subclinical and other myocardial pathologies. DE-MRI and when T1-mapping demonstrated sub-epicardium, sub-endocardial and patchy mid-myocardial enhancement in myocarditis, Behcet's disease and sarcoidosis, respectively. Furthermore, recent studies showed that the combined technique of cine, T2-weighted and DE-MRI technique has high diagnostic accuracy for detecting myocarditis. When the tomographic techniques are coupled with myocardial perfusion and left ventricular function they can provide valuable information on the progression of myocardial pathologies and effectiveness of new therapies.
