Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity an...Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity and superparamagnetism.However,it is still a great challenge to prepare ideal iron oxide based contrast agents with high uniformity,excellent water solubility and biocompatibility.In this paper,a novel water-soluble polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(N-vinyl-2-pyrrolidone)(PTMP-PVP)was used as a capping reagent to prepare iron oxide nanoparticles MIONs@PTMP-PVP through one-step co-precipitation of iron precursors in aqueous solution at 100℃.The obtained nanoparticles MIONs@PTMP-PVP had a small size and narrow size distribution,and they were found to be biocompatible as determined through CCK-8 assay and histology analysis.In vivo MRI study demonstrated that the obtained MIONs@PTMP-PVP can be potentially used as an effective T_(2)-weighted MRI contrast agent.展开更多
The tire acoustic cavity resonance(TACR)noise is a significant source of the structure-borne noise inside a vehicle in the low-frequency range.This paper studies the noise dissipation effect of porous materials in red...The tire acoustic cavity resonance(TACR)noise is a significant source of the structure-borne noise inside a vehicle in the low-frequency range.This paper studies the noise dissipation effect of porous materials in reducing the TACR noise,an attempt to clarify the acoustic reduction mechanism and improve the accompanying vehicle interior noise level.A numerical model of a simplified tire cavity with rigid boundaries and acoustic excitation is established and further validated by the experiment.The effects of porous parameters on TACR frequency and sound pressure are then investigated and compared.The result reveals that the most influential material parameters are the porosity and material volume.It is also shown that the effectiveness of porous material in the mitigation of noise originates from the curliness of the material,which results in much larger acoustic impedance near the excitation position.Therefore,the sound absorption performance of the cavity attached with porous material proves to be excellent compared to that of the porous material itself.For further studying the damping effects of structural coupling,the flexible boundary of the tire tread is introduced.The results show that the porosity,material volume and structural loss factor of the tread all play important roles in reducing TACR noise.展开更多
To clarify fluid flow mechanisms and establish effective development conditions in continental shale oil reservoirs,a high-temperature,high-pressure steady-state flow system integrated with nuclear magnetic resonance(...To clarify fluid flow mechanisms and establish effective development conditions in continental shale oil reservoirs,a high-temperature,high-pressure steady-state flow system integrated with nuclear magnetic resonance(NMR)technology has been developed.The apparatus combines sample evacuation,rapid pressurization and saturation,and controlled displacement,enabling systematic investigation of single-phase shale oil flow under representative reservoir conditions.Related experiments allow proper quantification of the activation thresholds and relative contributions of different pore types to flow.A movable fluid index(MFI),defined using dual T_(2) cutoff values,is introduced accordingly and linked to key flow parameters.The results reveal distinct multi-scale characteristics of single-phase shale oil transport,namely micro-scale graded displacement and macro-scale segmented nonlinear behavior.As the injection-production pressure difference increases,flow pathways are activated progressively,beginning with fractures,followed by large and then smaller macropores,leading to a pronounced enhancement in apparent permeability.Although mesopores and micropores contribute little to direct flow,their indirect influence becomes increasingly important,and apparent permeability gradually approaches a stable limit at higher pressure difference.It is also shown that the MFI exhibits a strong negative correlation with the starting pressure gradient and a positive correlation with apparent permeability,providing a rapid and reliable indicator of shale oil flow capacity.Samples containing through-going fractures display consistently higher MFI values and superior flowability compared with those dominated by laminated fractures,highlighting the pivotal role of well-connected fracture networks generated by large-scale hydraulic fracturing in improving shale oil production.展开更多
Magnetic resonance imaging(MRI)is a powerful tool for diagnosing and monitoring brain diseases,but its low sensitivity can hinder early detection.To address this challenge,we utilized chemical exchange saturation tran...Magnetic resonance imaging(MRI)is a powerful tool for diagnosing and monitoring brain diseases,but its low sensitivity can hinder early detection.To address this challenge,we utilized chemical exchange saturation transfer(CEST)MRI,which greatly enhances sensitivity for detecting low-concentration compounds.In this study,we developed a CEST contrast agent based on a recombinant adeno-associated viruses(rAAVs)encoding the protamine-1(PRM1)MRI reporter gene.CEST MRI revealed that PRM1 contrast agent effectively highlighted caudate putamen region after injection of the rAAVs into the mouse brain,clearly distinguishing it from the surrounding tissue,with no observable damage.This method provides a sensitive,metal-free CEST contrast agent for in vivo brain cell detection,demonstrating potential for both diagnostic and therapeutic applications in brain diseases.展开更多
AIM:To compare spontaneous brain regional activities between diabetic vitreous hemorrhage patients(DVHs)and healthy controls(HCs).METHODS:Thirty-two DVHs and 32 HCs were enrolled in this study.Baseline demographic and...AIM:To compare spontaneous brain regional activities between diabetic vitreous hemorrhage patients(DVHs)and healthy controls(HCs).METHODS:Thirty-two DVHs and 32 HCs were enrolled in this study.Baseline demographic and vision data were compared between groups using an independent sample t-test.Resting-state functional magnetic resonance imaging(rs-fMRI)was used in all participants.fMRI data was obtained and analyzed using MRIcro and SPM8 software.Fractional amplitude of low-frequency fluctuation(fALFF)technology was used to measure regional spontaneous brain activity,and sensitivity was tested using receiver operating characteristic curves(ROCs).The fALFF values were analyzed using REST software and two-sample t-tests were used to compare values between groups.Hospital anxiety and depression scale(HADS)score was assessed in DVHs and Pearson’s correlation was used to test relationships between mean fALFF value and both HADS score and duration of DVH.RESULTS:Except for the best-corrected visual acuity(BCVA)in both eyes,which showed a statistically significant difference(P<0.05),there were no statistically significant differences in the other indicators(P>0.05)between the HCs and DVHs group.Compared with controls,fALFF value was higher in DVH in cerebellum posterior lobe(CPL)and lower in right anterior cingulate cortex(ACC)and right medial orbitofrontal cortex(OFC).In DVH patients,mean fALFF value of CPL was positively correlated with HADS score and duration of diabetes.However,no such correlation was found,for right ACC or right medial OFC.DVH may lead to abnormal activities in certain brain regions related to visual control and mood.CONCLUSION:Visual impairment caused by DVH may lead to adjustment in regional visual brain activities and may be related to depression or reward system processing in some brain regions.展开更多
Freezing of gait is a significant and debilitating motor symptom often observed in individuals with Parkinson's disease.Resting-state functional magnetic resonance imaging,along with its multi-level feature indice...Freezing of gait is a significant and debilitating motor symptom often observed in individuals with Parkinson's disease.Resting-state functional magnetic resonance imaging,along with its multi-level feature indices,has provided a fresh perspective and valuable insight into the study of freezing of gait in Parkinson's disease.It has been revealed that Parkinson's disease is accompanied by widespread irregularities in inherent brain network activity.However,the effective integration of the multi-level indices of resting-state functional magnetic resonance imaging into clinical settings for the diagnosis of freezing of gait in Parkinson's disease remains a challenge.Although previous studies have demonstrated that radiomics can extract optimal features as biomarkers to identify or predict diseases,a knowledge gap still exists in the field of freezing of gait in Parkinson's disease.This cross-sectional study aimed to evaluate the ability of radiomics features based on multi-level indices of resting-state functional magnetic resonance imaging,along with clinical features,to distinguish between Parkinson's disease patients with and without freezing of gait.We recruited 28 patients with Parkinson's disease who had freezing of gait(15 men and 13 women,average age 63 years)and 30 patients with Parkinson's disease who had no freezing of gait(16 men and 14 women,average age 64 years).Magnetic resonance imaging scans were obtained using a 3.0T scanner to extract the mean amplitude of low-frequency fluctuations,mean regional homogeneity,and degree centrality.Neurological and clinical characteristics were also evaluated.We used the least absolute shrinkage and selection operator algorithm to extract features and established feedforward neural network models based solely on resting-state functional magnetic resonance imaging indicators.We then performed predictive analysis of three distinct groups based on resting-state functional magnetic resonance imaging indicators indicators combined with clinical features.Subsequently,we conducted 100 additional five-fold cross-validations to determine the most effective model for each classification task and evaluated the performance of the model using the area under the receiver operating characteristic curve.The results showed that when differentiating patients with Parkinson's disease who had freezing of gait from those who did not have freezing of gait,or from healthy controls,the models using only the mean regional homogeneity values achieved the highest area under the receiver operating characteristic curve values of 0.750(with an accuracy of 70.9%)and 0.759(with an accuracy of 65.3%),respectively.When classifying patients with Parkinson's disease who had freezing of gait from those who had no freezing of gait,the model using the mean amplitude of low-frequency fluctuation values combined with two clinical features achieved the highest area under the receiver operating characteristic curve of 0.847(with an accuracy of 74.3%).The most significant features for patients with Parkinson's disease who had freezing of gait were amplitude of low-frequency fluctuation alterations in the left parahippocampal gyrus and two clinical characteristics:Montreal Cognitive Assessment and Hamilton Depression Scale scores.Our findings suggest that radiomics features derived from resting-state functional magnetic resonance imaging indices and clinical information can serve as valuable indices for the identification of freezing of gait in Parkinson's disease.展开更多
The integration of a large number of power electronic converters,such as railway power conditioner(RPC),introduces a series of problems,including harmonic interaction,stability issues,and wideband resonance,into the r...The integration of a large number of power electronic converters,such as railway power conditioner(RPC),introduces a series of problems,including harmonic interaction,stability issues,and wideband resonance,into the railway power supply system.To address these challenges,this paper proposes a novel harmonic resonance prevention measure for RPC-network-train interaction system.Firstly,a harmonic model,a parallel resonance impedance model,a series resonance admittance model,and a control stability model are each established for the RPC-network-train interaction system.Secondly,a comprehensive resonance impact factor(CRIF)is proposed to efficiently and accurately identify the key components affecting resonance,and to provide the selection results of optimization parameters for resonance prevention.Next,the initially selected parameters are constrained by the requirements of ripple current,reactive power and stability.Subsequently,the impedance parameters(control parameters and filter parameters)of the RPC are optimized with the objective of reshaping the parallel resonance impedance and series resonance admittance of the RPC-network-train interaction system,ensuring the output current har-monics of RPC meet standards to achieve resonance prevention,while ensuring the stable operation of the RPC.Finally,the proposed resonance prevention measure is verified under both light load and heavy load conditions using a simulation platform and a hardware-in-the-loop experimental platform.展开更多
Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)is an advanced instrument capable of separating and determining molecular mass-to-charge ratios with sub-ppm level accuracy.A ...Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)is an advanced instrument capable of separating and determining molecular mass-to-charge ratios with sub-ppm level accuracy.A typical FT-ICR MS spectrogram can identify hundreds to thousands of formulas in a complex sample.This perspective briefly examines the application of FT-ICR MS to soil organic matter and plant biomass studies,highlighting their significant contributions to sustainable agriculture and environment.展开更多
Fetal intracranial tumors are rare,accounting for approximately 0.5%–1.9%of all pediatric tumors,though the true incidence may be underestimated.These tumors often present with distinct histopathological features,ima...Fetal intracranial tumors are rare,accounting for approximately 0.5%–1.9%of all pediatric tumors,though the true incidence may be underestimated.These tumors often present with distinct histopathological features,imaging characteristics,and clinical behavior compared to their postnatal counterparts.This review summarizes the current understanding of the prenatal diagnosis and characterization of fetal brain tumors,with a particular focus on the role of fetal magnetic resonance imaging(MRI).We discuss the advantages of advanced MR sequences in enhancing lesion detection and anatomical delineation following suspicious findings on obstetric ultrasound.Common tumor types encountered in utero—including teratomas,as-trocytomas,medulloblastomas,choroid plexus papillomas,and craniopharyngiomas—are reviewed in terms of imaging fea-tures,differential diagnosis,and clinical implications.Furthermore,the review addresses the diagnostic challenges,prognostic considerations,and the potential role of fetal MRI in guiding perinatal management and parental counseling.展开更多
BACKGROUND Patients harboring gene mutations like KRAS,NRAS,and BRAF demonstrate highly variable responses to chemotherapy,posing challenges for treatment optimization.Multiparametric magnetic resonance imaging(MRI),w...BACKGROUND Patients harboring gene mutations like KRAS,NRAS,and BRAF demonstrate highly variable responses to chemotherapy,posing challenges for treatment optimization.Multiparametric magnetic resonance imaging(MRI),with its noninvasive capability to assess tumor characteristics in detail,has shown promise in evaluating treatment response and predicting therapeutic outcomes.This technology holds potential for guiding personalized treatment strategies tailored to individual patient profiles,enhancing the precision and effectiveness of colorectal cancer care.AIM To create a multiparametric MRI-based predictive model for assessing chemotherapy efficacy in colorectal cancer patients with gene mutations.METHODS This retrospective study was conducted in a tertiary hospital,analyzing 157 colorectal cancer patients with gene mutations treated between August 2022 and December 2023.Based on chemotherapy outcomes,the patients were categorized into favorable(n=60)and unfavorable(n=50)response groups.Univariate and multivariate logistic regression analyses were performed to identify independent predictors of chemotherapy efficacy.A predictive nomogram was constructed using significant variables,and its performance was assessed using the area under the receiver operating characteristic curve(AUC)in both training and validation sets.RESULTS Univariate analysis identified that tumor differentiation,T2 signal intensity ratio,tumor-to-anal margin distance,and MRI-detected lymph node metastasis as significantly associated with chemotherapy response(P<0.05).Multivariate Logistics regression confirmed these four parameters as independent predictors.The predictive model demonstrated strong discrimination,with an AUC of 0.938(sensitivity:86%;specificity:92%)in the training set,and 0.942(sensitivity:100%;specificity:83%)in the validation set.CONCLUSION We established and validated a multiparametric MRI-based model for predicting chemotherapy response in colorectal cancer patients with gene mutations.This model holds promise for guiding individualized treatment strategies.展开更多
Background:Congenital hepatic hemangioma(CHH)is a rare benign vascular tumor that occurs prenatally.However,only a few cases have been summarized and evaluated for the prenatal and postnatal imaging features of CHH,an...Background:Congenital hepatic hemangioma(CHH)is a rare benign vascular tumor that occurs prenatally.However,only a few cases have been summarized and evaluated for the prenatal and postnatal imaging features of CHH,and no studies have conducted long-term follow-up on it.This study aimed to explore the ultrasound and magnetic resonance features,growth patterns,and clinical outcomes of CHH.Methods:Thirty-six pregnancies with a prenatal fetal diagnosis and postnatal diagnosis of CHH were studied.CHHs were grouped into those with a diameter≥4 cm and those with a diameter<4 cm according to the largest diameter.Fisher's exact test was used to compare the imaging characteristics between the groups.The volume of CHHs was measured at each follow-up visit to plot the growth pattern of the tumors,and the volume of CHHs was compared before and after birth using a rank sum test analysis.Results:Thirty-three cases of CHHs were confirmed by postnatal imaging,and three were confirmed by a biopsy.Mixed echoes were more common in the diameter≥4 cm group than in the diameter<4 cm group(p=0.026).Complications were more likely to occur in the large-diameter group.Eighteen(54.5%)cases were classified as rapidly involuting congenital hemangioma,nine(27.3%)as partially involuting congenital hemangioma,and two(6.1%)as noninvoluting congenital hemangioma.A new type of CHH was identified in which four(12.1%)cases continued to proliferate after birth and spontaneously subsided in subsequent months.The CHH volume decreased with age and was significantly decreased at 9 months postnatal compared to birth(p=0.001).Conclusion:This study showed the imaging features of CHH were associated with the lesion size.Based on postnatal follow-up,a new type of CHH was identified.If there are no complications at birth in CHH cases,a good prognosis is indicated.展开更多
Background:Magnetic resonance spectroscopy(MRS)represents a significant advancement in the noninvasive assessment of brain metabolism.MRS can provide valuable metabolic information and facilitate more accurate diagnos...Background:Magnetic resonance spectroscopy(MRS)represents a significant advancement in the noninvasive assessment of brain metabolism.MRS can provide valuable metabolic information and facilitate more accurate diagnoses of intrauterine fetal brain development than was previously possible.To obtain information regarding normal intrauterine fetal brain metabolism and to establish gestational age-specific reference values for normal fetal brain metabolites for subsequent use in MRS,we conducted MRS scans of normal fetal brains during mid-to late-term pregnancies,along with related processing.Methods:In this prospective study,MRS scans were conducted on 109 fetuses,with a total of 54 normal fetal brains enrolled on the basis of specific inclusion and exclusion criteria.We analyzed metabolic ratios,including the sum of N-acetylaspartate(NAA)and total N-acetylaspartate(tNAA),total choline(tCho),inositol(Ins),and total creatine(tCr),in relation to gestational age.Results:Gestational age was significantly correlated with specific metabolic ratios(Ins/tCr:r=-0.75,p<0.0001;tCho/tCr:r=-0.50,p<0.0001),especially tNAA/tCho(tNAA/tCho:r=0.54,p<0.0001)and tNAA/Ins(r=0.56,p<0.0001),providing a baseline for fetal brain metabolic assessment.Linear regression analysis was used to calculate regression lines for fetal brain metabolite ratios.Slopes were tested at p of 0.05.Conclusions:The current findings confirmed a significant correlation between fetal brain metabolites and gestational age,supporting the feasibility of establishing standard values for these metabolites in fetal brain assessment.展开更多
BACKGROUND An increasing number of studies to date have found preoperative magnetic resonance imaging(MRI)features valuable in predicting the prognosis of rectal cancer(RC).However,research is still lacking on the cor...BACKGROUND An increasing number of studies to date have found preoperative magnetic resonance imaging(MRI)features valuable in predicting the prognosis of rectal cancer(RC).However,research is still lacking on the correlation between preoperative MRI features and the risk of recurrence after radical resection of RC,urgently necessitating further in-depth exploration.AIM To investigate the correlation between preoperative MRI parameters and the risk of recurrence after radical resection of RC to provide an effective tool for predicting postoperative recurrence.METHODS The data of 90 patients who were diagnosed with RC by surgical pathology and underwent radical surgical resection at the Second Affiliated Hospital of Bengbu Medical University between May 2020 and December 2023 were collected through retrospective analysis.General demographic data,MRI data,and tumor markers levels were collected.According to the reviewed data of patients six months after surgery,the clinicians comprehensively assessed the recurrence risk and divided the patients into high recurrence risk(37 cases)and low recurrence risk(53 cases)groups.Independent sample t-test andχ2 test were used to analyze differences between the two groups.A logistic regression model was used to explore the risk factors of the high recurrence risk group,and a clinical prediction model was constructed.The clinical prediction model is presented in the form of a nomogram.The receiver operating characteristic curve,Hosmer-Lemeshow goodness of fit test,calibration curve,and decision curve analysis were used to evaluate the efficacy of the clinical prediction model.RESULTS The detection of positive extramural vascular invasion through preoperative MRI[odds ratio(OR)=4.29,P=0.045],along with elevated carcinoembryonic antigen(OR=1.08,P=0.041),carbohydrate antigen 125(OR=1.19,P=0.034),and carbohydrate antigen 199(OR=1.27,P<0.001)levels,are independent risk factors for increased postoperative recurrence risk in patients with RC.Furthermore,there was a correlation between magnetic resonance based T staging,magnetic resonance based N staging,and circumferential resection margin results determined by MRI and the postoperative recurrence risk.Additionally,when extramural vascular invasion was integrated with tumor markers,the resulting clinical prediction model more effectively identified patients at high risk for postoperative recurrence,thereby providing robust support for clinical decision-making.CONCLUSION The results of this study indicate that preoperative MRI detection is of great importance for predicting the risk of postoperative recurrence in patients with RC.Monitoring these markers helps clinicians identify patients at high risk,allowing for more aggressive treatment and monitoring strategies to improve patient outcomes.展开更多
BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)i...BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)is the most advanced nonin-vasive preoperative method.However,it is limited in its visualization function.AIM To investigate the use of intraluminal MRI for perianal fistulas via a novel direct MRI fistulography method.METHODS We mixed 3%hydrogen peroxide(HP)with gadolinium for HPMRI fistulogra-phy,retrospectively analyzing 60 cases of complex/recurrent fistula-in-ano using physical examination,trans-perineal ultrasonography(TPUS),low-spatial-reso-lution MRI,and high-resolution direct HPMRI fistulography.We assessed detec-tion rates of fistula tracks,internal openings,their relationship with anal sphinc-ters,and perianal abscesses using statistical analyses,including interobserver agreement(Kappa statistic),and compared results with intraoperative findings.RESULTS Surgical confirmation in 60 cases showed that high-resolution direct HPMRI fis-tulography provided superior detection rates for internal openings(153)and fistula tracks(162)compared to physical exams,TPUS,and low-spatial-resolution MRI(Z>5.7,P<0.05).The effectiveness of physical examination and TPUS was also inferior to that of our method for detecting perianal abscesses(54)(Z=6.773,3.694,P<0.05),whereas that of low-spatial-resolution MRI was not significantly different(Z=1.851,P=0.06).High-resolution direct HPMRI fistulography also achieved the highest interobserver agreement(Kappa:0.89,0.85,and 0.80),while low-spatial-resolution MRI showed moderate agreement(Kappa:0.78,0.74,and 0.69).TPUS and physical examination had lower agreement(Kappa range:0.33-0.63).CONCLUSION High-resolution direct HPMRI fistulography enhances the visualization of recurrent and complex fistula-in-ano,including branched fistulas,allowing for precise planning and improved surgical outcomes.展开更多
Angiomyolipomas(AMLs)represent the most common benign solid renal tumors.The frequency of their detection in the general population is increasing owing to advances in imaging technology.The objective of this review is...Angiomyolipomas(AMLs)represent the most common benign solid renal tumors.The frequency of their detection in the general population is increasing owing to advances in imaging technology.The objective of this review is to discuss computed tomography(CT)and magnetic resonance imaging findings for both typical and atypical renal AMLs,along with their associated complications.AMLs are typically defined as solid triphasic tumors composed of varying amounts of dysmorphic and tortuous blood vessels,smooth muscle components and adipose tissue.In an adult,a classical renal AML appears as a solid,heterogeneous renal cortical mass with macroscopic fat.However,up to 5%of AMLs contain minimal fat and cannot be reliably diagnosed by imaging.Fat-poor AMLs can appear as hyperattenuating masses on unenhanced CT and as hypointense masses on T2WI;other AMLs may be isodense or exhibit cystic components.Hemorrhage is the most common complication,and AMLs with hemorrhage can mimic other tumors,making their diagnosis challenging.Understanding the variable and heterogeneous nature of this neoplasm to correctly classify renal AMLs and to avoid misdiagnosis of other renal lesions is crucial.展开更多
The effects of plasma screening on the ^(1)P^(o) resonance states of H-and He below the n=3 and n=4 thresholds of the respective subsystemsare investigated using the stabilization method and correlated exponential wav...The effects of plasma screening on the ^(1)P^(o) resonance states of H-and He below the n=3 and n=4 thresholds of the respective subsystemsare investigated using the stabilization method and correlated exponential wave functions.Two plasma mediums,namely,the Debye plasma and quantum plasma environments are considered.The screened Coulomb potential(SCP)obtained from Debye-Hückel model is used to represent Debye plasma environments and the exponential cosine screened Coulomb potential(ECSCP)obtained from a modified Debye-Hückel model is used to represent quantum plasma environments.The resonance parameters(resonance positions and widths)are presented in terms of the screening parameters.展开更多
Historically,psychiatric diagnoses have been made based on patient’s reported symptoms applying the criteria from diagnostic and statistical manual of mental disorders.The utilization of neuroimaging or biomarkers to...Historically,psychiatric diagnoses have been made based on patient’s reported symptoms applying the criteria from diagnostic and statistical manual of mental disorders.The utilization of neuroimaging or biomarkers to make the diagnosis and manage psychiatric disorders remains a distant goal.There have been several studies that examine brain imaging in psychiatric disorders,but more work is needed to elucidate the complexities of the human brain.In this editorial,we examine two articles by Xu et al and Stoyanov et al,that show developments in the direction of using neuroimaging to examine the brains of people with schizo-phrenia and depression.Xu et al used magnetic resonance imaging to examine the brain structure of patients with schizophrenia,in addition to examining neurotransmitter levels as biomarkers.Stoyanov et al used functional magnetic resonance imaging to look at modulation of different neural circuits by diagnostic-specific scales in patients with schizophrenia and depression.These two studies provide crucial evidence in advancing our understanding of the brain in prevalent psychiatric disorders.展开更多
Metal micro-nano grating has received much attention due to its ability to provide high-efficiency light absorption.However,the current research scales of these metal gratings are focused on subwavelengths,and little ...Metal micro-nano grating has received much attention due to its ability to provide high-efficiency light absorption.However,the current research scales of these metal gratings are focused on subwavelengths,and little attention has been paid to the absorption properties of metal gratings at other scales.We investigate the absorption properties of metal gratings based on surface plasmon resonance(SPR)across the scales from superwavelength to subwavelength.Under grazing incidence,we observe continuous strong absorption phenomena from superwavelength to subwavelength Al triangle-groove gratings(TGGs).Perfect absorption is realized at the subwavelength scale,whereas the maximum absorption at all other scales exceeds 74%.The electric field distribution gives the mechanism of the strong absorption phenomenon attributed to SPR on the surface of Al TGGs at different scales.In particular,subwavelength Al TGGs have perfectly symmetric absorption properties for different blaze angles,and the symmetry is gradually broken as the grating period’s scale increases.Furthermore,taking Al gratings with varying groove shapes for example,we extend the equivalence rule of grating grooves to subwavelength from near-wavelength and explain the symmetric absorption properties in Al TGGs.We unify the research of metal grating absorbers outside the subwavelength scale to a certain extent,and these findings also open new perspectives for the design of metal gratings in the future.展开更多
BACKGROUND Transcatheter arterial chemoembolization(TACE)is a key treatment approach for advanced invasive liver cancer(infiltrative hepatocellular carcinoma).However,its therapeutic response can be difficult to evalu...BACKGROUND Transcatheter arterial chemoembolization(TACE)is a key treatment approach for advanced invasive liver cancer(infiltrative hepatocellular carcinoma).However,its therapeutic response can be difficult to evaluate accurately using conventional two-dimensional imaging criteria due to the tumor’s diffuse and multifocal growth pattern.Volumetric imaging,especially enhanced tumor volume(ETV),offers a more comprehensive assessment.Nonetheless,bias field inhomogeneity in magnetic resonance imaging(MRI)poses challenges,potentially skewing volumetric measurements and undermining prognostic evaluation.AIM To investigate whether MRI bias field correction enhances the accuracy of volumetric assessment of infiltrative hepatocellular carcinoma treated with TACE,and to analyze how this improved measurement impacts prognostic prediction.METHODS We retrospectively collected data from 105 patients with invasive liver cancer who underwent TACE treatment at the Affiliated Hospital of Xuzhou Medical University from January 2020 to January 2024.The improved N4 bias field correction algorithm was applied to process MRI images,and the ETV before and after treatment was calculated.The ETV measurements before and after correction were compared,and their relationship with patient prognosis was analyzed.A Cox proportional hazards model was used to evaluate prognostic factors,with Martingale residual analysis determining the optimal cutoff value,followed by survival analysis.RESULTS Bias field correction significantly affected ETV measurements,with the corrected baseline ETV mean(505.235 cm^(3))being significantly lower than before correction(825.632 cm^(3),P<0.001).Cox analysis showed that the hazard ratio(HR)for corrected baseline ETV(HR=1.165,95%CI:1.069-1.268)was higher than before correction(HR=1.063,95%CI:1.031-1.095).Using 412 cm^(3) as the cutoff,the group with baseline ETV<415 cm^(3) had a longer median survival time compared to the≥415 cm^(3) group(18.523 months vs 8.926 months,P<0.001).The group with an ETV reduction rate≥41%had better prognosis than the<41%group(17.862 months vs 9.235 months,P=0.006).Multivariate analysis confirmed that ETV reduction rate(HR=0.412,P<0.001),Child-Pugh classification(HR=0.298,P<0.001),and Barcelona Clinic Liver Cancer stage(HR=0.578,P=0.045)were independent prognostic factors.CONCLUSION Volume imaging based on MRI bias field correction can improve the accuracy of evaluating the efficacy of TACE treatment for invasive liver cancer.The corrected ETV and its reduction rate can serve as independent indicators for predicting patient prognosis,providing important reference for developing individualized treatment strategies.展开更多
BACKGROUND Obstructed defecation syndrome(ODS)is a subtype of constipation that is consi-dered one of the major pelvic floor dysfunctions affecting the aging population,particularly women over 50 seeking medical care....BACKGROUND Obstructed defecation syndrome(ODS)is a subtype of constipation that is consi-dered one of the major pelvic floor dysfunctions affecting the aging population,particularly women over 50 seeking medical care.The condition is characterized by the urge to defecate but an impaired ability to expel the fecal bolus.ODS is associated with various anorectal abnormalities,which are not always apparent during a standard physical examination,requiring specialized imaging techniques for proper diagnosis.AIM To study the distribution of causes of ODS in patients with chronic constipation by magnetic resonance defecography(MRD).METHODS This observational study evaluated the causes of ODS in 57 patients with chronic constipation who presented to Bangabandhu Sheikh Mujib Medical University between July 2020 and June 2021.After obtaining institutional review board approval and informed consent,patients underwent history taking,physical exams,and relevant investigations.ODS was diagnosed using Rome III criteria,with colonoscopy ruling out organic causes.Standard MRD was performed in different phases,and images were analyzed by expert radiologists and reported in a stan-dardized format.RESULTS Pelvic floor descent and anorectal junction descent were the most frequent findings,each present in 94.7%of cases.Rectocele was observed in 78.9%of patients,while vaginal or uterine prolapse was seen in 59.4%of females.Less common abnormalities included paradoxical contraction(7%),and there were no cases of sigmoidocele.Functional measurements showed significant differences in pelvic floor dynamics between rest and defecation,particularly in the H-line,M-line,and descent of pelvic organs(P<0.05).CONCLUSION Pelvic floor descent and anorectal descent were the most common findings in patients suffering from ODS,fo-llowed by rectocele.Younger females(<30 years)were most affected.展开更多
基金financially supported by the International Cooperation Program from the Ministry of Science and Technology of Hubei Province(No.2023EHA069)Shenzhen Science and Technology Program(No.JCYJ20230807143702005)National Foreign Experts Program(No.G2022027015L)。
文摘Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity and superparamagnetism.However,it is still a great challenge to prepare ideal iron oxide based contrast agents with high uniformity,excellent water solubility and biocompatibility.In this paper,a novel water-soluble polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(N-vinyl-2-pyrrolidone)(PTMP-PVP)was used as a capping reagent to prepare iron oxide nanoparticles MIONs@PTMP-PVP through one-step co-precipitation of iron precursors in aqueous solution at 100℃.The obtained nanoparticles MIONs@PTMP-PVP had a small size and narrow size distribution,and they were found to be biocompatible as determined through CCK-8 assay and histology analysis.In vivo MRI study demonstrated that the obtained MIONs@PTMP-PVP can be potentially used as an effective T_(2)-weighted MRI contrast agent.
基金Supported by National Natural Science Foundation of China(Grant No.51675021).
文摘The tire acoustic cavity resonance(TACR)noise is a significant source of the structure-borne noise inside a vehicle in the low-frequency range.This paper studies the noise dissipation effect of porous materials in reducing the TACR noise,an attempt to clarify the acoustic reduction mechanism and improve the accompanying vehicle interior noise level.A numerical model of a simplified tire cavity with rigid boundaries and acoustic excitation is established and further validated by the experiment.The effects of porous parameters on TACR frequency and sound pressure are then investigated and compared.The result reveals that the most influential material parameters are the porosity and material volume.It is also shown that the effectiveness of porous material in the mitigation of noise originates from the curliness of the material,which results in much larger acoustic impedance near the excitation position.Therefore,the sound absorption performance of the cavity attached with porous material proves to be excellent compared to that of the porous material itself.For further studying the damping effects of structural coupling,the flexible boundary of the tire tread is introduced.The results show that the porosity,material volume and structural loss factor of the tread all play important roles in reducing TACR noise.
基金supported by the National Science and Technology Major Project of China(Grant No.2024ZD 1004302)the Key Scientific and Technological Research project of SINOPEC(Grant No.P25186).
文摘To clarify fluid flow mechanisms and establish effective development conditions in continental shale oil reservoirs,a high-temperature,high-pressure steady-state flow system integrated with nuclear magnetic resonance(NMR)technology has been developed.The apparatus combines sample evacuation,rapid pressurization and saturation,and controlled displacement,enabling systematic investigation of single-phase shale oil flow under representative reservoir conditions.Related experiments allow proper quantification of the activation thresholds and relative contributions of different pore types to flow.A movable fluid index(MFI),defined using dual T_(2) cutoff values,is introduced accordingly and linked to key flow parameters.The results reveal distinct multi-scale characteristics of single-phase shale oil transport,namely micro-scale graded displacement and macro-scale segmented nonlinear behavior.As the injection-production pressure difference increases,flow pathways are activated progressively,beginning with fractures,followed by large and then smaller macropores,leading to a pronounced enhancement in apparent permeability.Although mesopores and micropores contribute little to direct flow,their indirect influence becomes increasingly important,and apparent permeability gradually approaches a stable limit at higher pressure difference.It is also shown that the MFI exhibits a strong negative correlation with the starting pressure gradient and a positive correlation with apparent permeability,providing a rapid and reliable indicator of shale oil flow capacity.Samples containing through-going fractures display consistently higher MFI values and superior flowability compared with those dominated by laminated fractures,highlighting the pivotal role of well-connected fracture networks generated by large-scale hydraulic fracturing in improving shale oil production.
基金financially supported by the National Natural Science Foundation of China(82127802,22374157)Strategic Priority Research Program,CAS(XDB0540000,XDC0170000)CAS Youth Interdisciplinary Team(JCTD-2022-13).In addition,Xin Zhou acknowledges the support from the Tencent Foundation through the XPLORER PRIZE.
文摘Magnetic resonance imaging(MRI)is a powerful tool for diagnosing and monitoring brain diseases,but its low sensitivity can hinder early detection.To address this challenge,we utilized chemical exchange saturation transfer(CEST)MRI,which greatly enhances sensitivity for detecting low-concentration compounds.In this study,we developed a CEST contrast agent based on a recombinant adeno-associated viruses(rAAVs)encoding the protamine-1(PRM1)MRI reporter gene.CEST MRI revealed that PRM1 contrast agent effectively highlighted caudate putamen region after injection of the rAAVs into the mouse brain,clearly distinguishing it from the surrounding tissue,with no observable damage.This method provides a sensitive,metal-free CEST contrast agent for in vivo brain cell detection,demonstrating potential for both diagnostic and therapeutic applications in brain diseases.
基金Supported by National Natural Science Foundation of China(No.82160195,No.82460203)Zhejiang Traditional Chinese Medicine Science and Technology Plan Project(No.2025ZR172).
文摘AIM:To compare spontaneous brain regional activities between diabetic vitreous hemorrhage patients(DVHs)and healthy controls(HCs).METHODS:Thirty-two DVHs and 32 HCs were enrolled in this study.Baseline demographic and vision data were compared between groups using an independent sample t-test.Resting-state functional magnetic resonance imaging(rs-fMRI)was used in all participants.fMRI data was obtained and analyzed using MRIcro and SPM8 software.Fractional amplitude of low-frequency fluctuation(fALFF)technology was used to measure regional spontaneous brain activity,and sensitivity was tested using receiver operating characteristic curves(ROCs).The fALFF values were analyzed using REST software and two-sample t-tests were used to compare values between groups.Hospital anxiety and depression scale(HADS)score was assessed in DVHs and Pearson’s correlation was used to test relationships between mean fALFF value and both HADS score and duration of DVH.RESULTS:Except for the best-corrected visual acuity(BCVA)in both eyes,which showed a statistically significant difference(P<0.05),there were no statistically significant differences in the other indicators(P>0.05)between the HCs and DVHs group.Compared with controls,fALFF value was higher in DVH in cerebellum posterior lobe(CPL)and lower in right anterior cingulate cortex(ACC)and right medial orbitofrontal cortex(OFC).In DVH patients,mean fALFF value of CPL was positively correlated with HADS score and duration of diabetes.However,no such correlation was found,for right ACC or right medial OFC.DVH may lead to abnormal activities in certain brain regions related to visual control and mood.CONCLUSION:Visual impairment caused by DVH may lead to adjustment in regional visual brain activities and may be related to depression or reward system processing in some brain regions.
基金supported by the National Natural Science Foundation of China,No.82071909(to GF)the Natural Science Foundation of Liaoning Province,No.2023-MS-07(to HL)。
文摘Freezing of gait is a significant and debilitating motor symptom often observed in individuals with Parkinson's disease.Resting-state functional magnetic resonance imaging,along with its multi-level feature indices,has provided a fresh perspective and valuable insight into the study of freezing of gait in Parkinson's disease.It has been revealed that Parkinson's disease is accompanied by widespread irregularities in inherent brain network activity.However,the effective integration of the multi-level indices of resting-state functional magnetic resonance imaging into clinical settings for the diagnosis of freezing of gait in Parkinson's disease remains a challenge.Although previous studies have demonstrated that radiomics can extract optimal features as biomarkers to identify or predict diseases,a knowledge gap still exists in the field of freezing of gait in Parkinson's disease.This cross-sectional study aimed to evaluate the ability of radiomics features based on multi-level indices of resting-state functional magnetic resonance imaging,along with clinical features,to distinguish between Parkinson's disease patients with and without freezing of gait.We recruited 28 patients with Parkinson's disease who had freezing of gait(15 men and 13 women,average age 63 years)and 30 patients with Parkinson's disease who had no freezing of gait(16 men and 14 women,average age 64 years).Magnetic resonance imaging scans were obtained using a 3.0T scanner to extract the mean amplitude of low-frequency fluctuations,mean regional homogeneity,and degree centrality.Neurological and clinical characteristics were also evaluated.We used the least absolute shrinkage and selection operator algorithm to extract features and established feedforward neural network models based solely on resting-state functional magnetic resonance imaging indicators.We then performed predictive analysis of three distinct groups based on resting-state functional magnetic resonance imaging indicators indicators combined with clinical features.Subsequently,we conducted 100 additional five-fold cross-validations to determine the most effective model for each classification task and evaluated the performance of the model using the area under the receiver operating characteristic curve.The results showed that when differentiating patients with Parkinson's disease who had freezing of gait from those who did not have freezing of gait,or from healthy controls,the models using only the mean regional homogeneity values achieved the highest area under the receiver operating characteristic curve values of 0.750(with an accuracy of 70.9%)and 0.759(with an accuracy of 65.3%),respectively.When classifying patients with Parkinson's disease who had freezing of gait from those who had no freezing of gait,the model using the mean amplitude of low-frequency fluctuation values combined with two clinical features achieved the highest area under the receiver operating characteristic curve of 0.847(with an accuracy of 74.3%).The most significant features for patients with Parkinson's disease who had freezing of gait were amplitude of low-frequency fluctuation alterations in the left parahippocampal gyrus and two clinical characteristics:Montreal Cognitive Assessment and Hamilton Depression Scale scores.Our findings suggest that radiomics features derived from resting-state functional magnetic resonance imaging indices and clinical information can serve as valuable indices for the identification of freezing of gait in Parkinson's disease.
基金supported in part by the National Natural Science Foundation of China under Grant No.52277126.
文摘The integration of a large number of power electronic converters,such as railway power conditioner(RPC),introduces a series of problems,including harmonic interaction,stability issues,and wideband resonance,into the railway power supply system.To address these challenges,this paper proposes a novel harmonic resonance prevention measure for RPC-network-train interaction system.Firstly,a harmonic model,a parallel resonance impedance model,a series resonance admittance model,and a control stability model are each established for the RPC-network-train interaction system.Secondly,a comprehensive resonance impact factor(CRIF)is proposed to efficiently and accurately identify the key components affecting resonance,and to provide the selection results of optimization parameters for resonance prevention.Next,the initially selected parameters are constrained by the requirements of ripple current,reactive power and stability.Subsequently,the impedance parameters(control parameters and filter parameters)of the RPC are optimized with the objective of reshaping the parallel resonance impedance and series resonance admittance of the RPC-network-train interaction system,ensuring the output current har-monics of RPC meet standards to achieve resonance prevention,while ensuring the stable operation of the RPC.Finally,the proposed resonance prevention measure is verified under both light load and heavy load conditions using a simulation platform and a hardware-in-the-loop experimental platform.
文摘Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)is an advanced instrument capable of separating and determining molecular mass-to-charge ratios with sub-ppm level accuracy.A typical FT-ICR MS spectrogram can identify hundreds to thousands of formulas in a complex sample.This perspective briefly examines the application of FT-ICR MS to soil organic matter and plant biomass studies,highlighting their significant contributions to sustainable agriculture and environment.
基金supported by the Medical Innovation Research Special Project of Science and Technology Commission of Shanghai Municipality(Grant/Award Number:23Y11907800)Fundamental Research Funds for the Central Universities(Grant/Award Number:YG2023ZD22)Shanghai Key Laboratory of Child Brain and Development(Grant/Award Number:24dz2260100).
文摘Fetal intracranial tumors are rare,accounting for approximately 0.5%–1.9%of all pediatric tumors,though the true incidence may be underestimated.These tumors often present with distinct histopathological features,imaging characteristics,and clinical behavior compared to their postnatal counterparts.This review summarizes the current understanding of the prenatal diagnosis and characterization of fetal brain tumors,with a particular focus on the role of fetal magnetic resonance imaging(MRI).We discuss the advantages of advanced MR sequences in enhancing lesion detection and anatomical delineation following suspicious findings on obstetric ultrasound.Common tumor types encountered in utero—including teratomas,as-trocytomas,medulloblastomas,choroid plexus papillomas,and craniopharyngiomas—are reviewed in terms of imaging fea-tures,differential diagnosis,and clinical implications.Furthermore,the review addresses the diagnostic challenges,prognostic considerations,and the potential role of fetal MRI in guiding perinatal management and parental counseling.
基金Supported by Shenzhen High-level Hospital Construction Fund.
文摘BACKGROUND Patients harboring gene mutations like KRAS,NRAS,and BRAF demonstrate highly variable responses to chemotherapy,posing challenges for treatment optimization.Multiparametric magnetic resonance imaging(MRI),with its noninvasive capability to assess tumor characteristics in detail,has shown promise in evaluating treatment response and predicting therapeutic outcomes.This technology holds potential for guiding personalized treatment strategies tailored to individual patient profiles,enhancing the precision and effectiveness of colorectal cancer care.AIM To create a multiparametric MRI-based predictive model for assessing chemotherapy efficacy in colorectal cancer patients with gene mutations.METHODS This retrospective study was conducted in a tertiary hospital,analyzing 157 colorectal cancer patients with gene mutations treated between August 2022 and December 2023.Based on chemotherapy outcomes,the patients were categorized into favorable(n=60)and unfavorable(n=50)response groups.Univariate and multivariate logistic regression analyses were performed to identify independent predictors of chemotherapy efficacy.A predictive nomogram was constructed using significant variables,and its performance was assessed using the area under the receiver operating characteristic curve(AUC)in both training and validation sets.RESULTS Univariate analysis identified that tumor differentiation,T2 signal intensity ratio,tumor-to-anal margin distance,and MRI-detected lymph node metastasis as significantly associated with chemotherapy response(P<0.05).Multivariate Logistics regression confirmed these four parameters as independent predictors.The predictive model demonstrated strong discrimination,with an AUC of 0.938(sensitivity:86%;specificity:92%)in the training set,and 0.942(sensitivity:100%;specificity:83%)in the validation set.CONCLUSION We established and validated a multiparametric MRI-based model for predicting chemotherapy response in colorectal cancer patients with gene mutations.This model holds promise for guiding individualized treatment strategies.
文摘Background:Congenital hepatic hemangioma(CHH)is a rare benign vascular tumor that occurs prenatally.However,only a few cases have been summarized and evaluated for the prenatal and postnatal imaging features of CHH,and no studies have conducted long-term follow-up on it.This study aimed to explore the ultrasound and magnetic resonance features,growth patterns,and clinical outcomes of CHH.Methods:Thirty-six pregnancies with a prenatal fetal diagnosis and postnatal diagnosis of CHH were studied.CHHs were grouped into those with a diameter≥4 cm and those with a diameter<4 cm according to the largest diameter.Fisher's exact test was used to compare the imaging characteristics between the groups.The volume of CHHs was measured at each follow-up visit to plot the growth pattern of the tumors,and the volume of CHHs was compared before and after birth using a rank sum test analysis.Results:Thirty-three cases of CHHs were confirmed by postnatal imaging,and three were confirmed by a biopsy.Mixed echoes were more common in the diameter≥4 cm group than in the diameter<4 cm group(p=0.026).Complications were more likely to occur in the large-diameter group.Eighteen(54.5%)cases were classified as rapidly involuting congenital hemangioma,nine(27.3%)as partially involuting congenital hemangioma,and two(6.1%)as noninvoluting congenital hemangioma.A new type of CHH was identified in which four(12.1%)cases continued to proliferate after birth and spontaneously subsided in subsequent months.The CHH volume decreased with age and was significantly decreased at 9 months postnatal compared to birth(p=0.001).Conclusion:This study showed the imaging features of CHH were associated with the lesion size.Based on postnatal follow-up,a new type of CHH was identified.If there are no complications at birth in CHH cases,a good prognosis is indicated.
基金supported by China Society for Maternal and Child Health Research(Gant/Award Number:2023CAMCHS003A17).
文摘Background:Magnetic resonance spectroscopy(MRS)represents a significant advancement in the noninvasive assessment of brain metabolism.MRS can provide valuable metabolic information and facilitate more accurate diagnoses of intrauterine fetal brain development than was previously possible.To obtain information regarding normal intrauterine fetal brain metabolism and to establish gestational age-specific reference values for normal fetal brain metabolites for subsequent use in MRS,we conducted MRS scans of normal fetal brains during mid-to late-term pregnancies,along with related processing.Methods:In this prospective study,MRS scans were conducted on 109 fetuses,with a total of 54 normal fetal brains enrolled on the basis of specific inclusion and exclusion criteria.We analyzed metabolic ratios,including the sum of N-acetylaspartate(NAA)and total N-acetylaspartate(tNAA),total choline(tCho),inositol(Ins),and total creatine(tCr),in relation to gestational age.Results:Gestational age was significantly correlated with specific metabolic ratios(Ins/tCr:r=-0.75,p<0.0001;tCho/tCr:r=-0.50,p<0.0001),especially tNAA/tCho(tNAA/tCho:r=0.54,p<0.0001)and tNAA/Ins(r=0.56,p<0.0001),providing a baseline for fetal brain metabolic assessment.Linear regression analysis was used to calculate regression lines for fetal brain metabolite ratios.Slopes were tested at p of 0.05.Conclusions:The current findings confirmed a significant correlation between fetal brain metabolites and gestational age,supporting the feasibility of establishing standard values for these metabolites in fetal brain assessment.
文摘BACKGROUND An increasing number of studies to date have found preoperative magnetic resonance imaging(MRI)features valuable in predicting the prognosis of rectal cancer(RC).However,research is still lacking on the correlation between preoperative MRI features and the risk of recurrence after radical resection of RC,urgently necessitating further in-depth exploration.AIM To investigate the correlation between preoperative MRI parameters and the risk of recurrence after radical resection of RC to provide an effective tool for predicting postoperative recurrence.METHODS The data of 90 patients who were diagnosed with RC by surgical pathology and underwent radical surgical resection at the Second Affiliated Hospital of Bengbu Medical University between May 2020 and December 2023 were collected through retrospective analysis.General demographic data,MRI data,and tumor markers levels were collected.According to the reviewed data of patients six months after surgery,the clinicians comprehensively assessed the recurrence risk and divided the patients into high recurrence risk(37 cases)and low recurrence risk(53 cases)groups.Independent sample t-test andχ2 test were used to analyze differences between the two groups.A logistic regression model was used to explore the risk factors of the high recurrence risk group,and a clinical prediction model was constructed.The clinical prediction model is presented in the form of a nomogram.The receiver operating characteristic curve,Hosmer-Lemeshow goodness of fit test,calibration curve,and decision curve analysis were used to evaluate the efficacy of the clinical prediction model.RESULTS The detection of positive extramural vascular invasion through preoperative MRI[odds ratio(OR)=4.29,P=0.045],along with elevated carcinoembryonic antigen(OR=1.08,P=0.041),carbohydrate antigen 125(OR=1.19,P=0.034),and carbohydrate antigen 199(OR=1.27,P<0.001)levels,are independent risk factors for increased postoperative recurrence risk in patients with RC.Furthermore,there was a correlation between magnetic resonance based T staging,magnetic resonance based N staging,and circumferential resection margin results determined by MRI and the postoperative recurrence risk.Additionally,when extramural vascular invasion was integrated with tumor markers,the resulting clinical prediction model more effectively identified patients at high risk for postoperative recurrence,thereby providing robust support for clinical decision-making.CONCLUSION The results of this study indicate that preoperative MRI detection is of great importance for predicting the risk of postoperative recurrence in patients with RC.Monitoring these markers helps clinicians identify patients at high risk,allowing for more aggressive treatment and monitoring strategies to improve patient outcomes.
基金Supported by Bozhou Key Research and Development Project,No.bzzc2020031.
文摘BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)is the most advanced nonin-vasive preoperative method.However,it is limited in its visualization function.AIM To investigate the use of intraluminal MRI for perianal fistulas via a novel direct MRI fistulography method.METHODS We mixed 3%hydrogen peroxide(HP)with gadolinium for HPMRI fistulogra-phy,retrospectively analyzing 60 cases of complex/recurrent fistula-in-ano using physical examination,trans-perineal ultrasonography(TPUS),low-spatial-reso-lution MRI,and high-resolution direct HPMRI fistulography.We assessed detec-tion rates of fistula tracks,internal openings,their relationship with anal sphinc-ters,and perianal abscesses using statistical analyses,including interobserver agreement(Kappa statistic),and compared results with intraoperative findings.RESULTS Surgical confirmation in 60 cases showed that high-resolution direct HPMRI fis-tulography provided superior detection rates for internal openings(153)and fistula tracks(162)compared to physical exams,TPUS,and low-spatial-resolution MRI(Z>5.7,P<0.05).The effectiveness of physical examination and TPUS was also inferior to that of our method for detecting perianal abscesses(54)(Z=6.773,3.694,P<0.05),whereas that of low-spatial-resolution MRI was not significantly different(Z=1.851,P=0.06).High-resolution direct HPMRI fistulography also achieved the highest interobserver agreement(Kappa:0.89,0.85,and 0.80),while low-spatial-resolution MRI showed moderate agreement(Kappa:0.78,0.74,and 0.69).TPUS and physical examination had lower agreement(Kappa range:0.33-0.63).CONCLUSION High-resolution direct HPMRI fistulography enhances the visualization of recurrent and complex fistula-in-ano,including branched fistulas,allowing for precise planning and improved surgical outcomes.
文摘Angiomyolipomas(AMLs)represent the most common benign solid renal tumors.The frequency of their detection in the general population is increasing owing to advances in imaging technology.The objective of this review is to discuss computed tomography(CT)and magnetic resonance imaging findings for both typical and atypical renal AMLs,along with their associated complications.AMLs are typically defined as solid triphasic tumors composed of varying amounts of dysmorphic and tortuous blood vessels,smooth muscle components and adipose tissue.In an adult,a classical renal AML appears as a solid,heterogeneous renal cortical mass with macroscopic fat.However,up to 5%of AMLs contain minimal fat and cannot be reliably diagnosed by imaging.Fat-poor AMLs can appear as hyperattenuating masses on unenhanced CT and as hypointense masses on T2WI;other AMLs may be isodense or exhibit cystic components.Hemorrhage is the most common complication,and AMLs with hemorrhage can mimic other tumors,making their diagnosis challenging.Understanding the variable and heterogeneous nature of this neoplasm to correctly classify renal AMLs and to avoid misdiagnosis of other renal lesions is crucial.
基金Supported by the Natural Science Foundation of Heilongjiang Province(LH2024A025)。
文摘The effects of plasma screening on the ^(1)P^(o) resonance states of H-and He below the n=3 and n=4 thresholds of the respective subsystemsare investigated using the stabilization method and correlated exponential wave functions.Two plasma mediums,namely,the Debye plasma and quantum plasma environments are considered.The screened Coulomb potential(SCP)obtained from Debye-Hückel model is used to represent Debye plasma environments and the exponential cosine screened Coulomb potential(ECSCP)obtained from a modified Debye-Hückel model is used to represent quantum plasma environments.The resonance parameters(resonance positions and widths)are presented in terms of the screening parameters.
文摘Historically,psychiatric diagnoses have been made based on patient’s reported symptoms applying the criteria from diagnostic and statistical manual of mental disorders.The utilization of neuroimaging or biomarkers to make the diagnosis and manage psychiatric disorders remains a distant goal.There have been several studies that examine brain imaging in psychiatric disorders,but more work is needed to elucidate the complexities of the human brain.In this editorial,we examine two articles by Xu et al and Stoyanov et al,that show developments in the direction of using neuroimaging to examine the brains of people with schizo-phrenia and depression.Xu et al used magnetic resonance imaging to examine the brain structure of patients with schizophrenia,in addition to examining neurotransmitter levels as biomarkers.Stoyanov et al used functional magnetic resonance imaging to look at modulation of different neural circuits by diagnostic-specific scales in patients with schizophrenia and depression.These two studies provide crucial evidence in advancing our understanding of the brain in prevalent psychiatric disorders.
基金upported by the Guangdong Provincial Pearl River Talents Program(Grant No.2019ZT08Z779)the National Natural Science Foundation of China(Grant Nos.U21A20509 and 62205124).
文摘Metal micro-nano grating has received much attention due to its ability to provide high-efficiency light absorption.However,the current research scales of these metal gratings are focused on subwavelengths,and little attention has been paid to the absorption properties of metal gratings at other scales.We investigate the absorption properties of metal gratings based on surface plasmon resonance(SPR)across the scales from superwavelength to subwavelength.Under grazing incidence,we observe continuous strong absorption phenomena from superwavelength to subwavelength Al triangle-groove gratings(TGGs).Perfect absorption is realized at the subwavelength scale,whereas the maximum absorption at all other scales exceeds 74%.The electric field distribution gives the mechanism of the strong absorption phenomenon attributed to SPR on the surface of Al TGGs at different scales.In particular,subwavelength Al TGGs have perfectly symmetric absorption properties for different blaze angles,and the symmetry is gradually broken as the grating period’s scale increases.Furthermore,taking Al gratings with varying groove shapes for example,we extend the equivalence rule of grating grooves to subwavelength from near-wavelength and explain the symmetric absorption properties in Al TGGs.We unify the research of metal grating absorbers outside the subwavelength scale to a certain extent,and these findings also open new perspectives for the design of metal gratings in the future.
文摘BACKGROUND Transcatheter arterial chemoembolization(TACE)is a key treatment approach for advanced invasive liver cancer(infiltrative hepatocellular carcinoma).However,its therapeutic response can be difficult to evaluate accurately using conventional two-dimensional imaging criteria due to the tumor’s diffuse and multifocal growth pattern.Volumetric imaging,especially enhanced tumor volume(ETV),offers a more comprehensive assessment.Nonetheless,bias field inhomogeneity in magnetic resonance imaging(MRI)poses challenges,potentially skewing volumetric measurements and undermining prognostic evaluation.AIM To investigate whether MRI bias field correction enhances the accuracy of volumetric assessment of infiltrative hepatocellular carcinoma treated with TACE,and to analyze how this improved measurement impacts prognostic prediction.METHODS We retrospectively collected data from 105 patients with invasive liver cancer who underwent TACE treatment at the Affiliated Hospital of Xuzhou Medical University from January 2020 to January 2024.The improved N4 bias field correction algorithm was applied to process MRI images,and the ETV before and after treatment was calculated.The ETV measurements before and after correction were compared,and their relationship with patient prognosis was analyzed.A Cox proportional hazards model was used to evaluate prognostic factors,with Martingale residual analysis determining the optimal cutoff value,followed by survival analysis.RESULTS Bias field correction significantly affected ETV measurements,with the corrected baseline ETV mean(505.235 cm^(3))being significantly lower than before correction(825.632 cm^(3),P<0.001).Cox analysis showed that the hazard ratio(HR)for corrected baseline ETV(HR=1.165,95%CI:1.069-1.268)was higher than before correction(HR=1.063,95%CI:1.031-1.095).Using 412 cm^(3) as the cutoff,the group with baseline ETV<415 cm^(3) had a longer median survival time compared to the≥415 cm^(3) group(18.523 months vs 8.926 months,P<0.001).The group with an ETV reduction rate≥41%had better prognosis than the<41%group(17.862 months vs 9.235 months,P=0.006).Multivariate analysis confirmed that ETV reduction rate(HR=0.412,P<0.001),Child-Pugh classification(HR=0.298,P<0.001),and Barcelona Clinic Liver Cancer stage(HR=0.578,P=0.045)were independent prognostic factors.CONCLUSION Volume imaging based on MRI bias field correction can improve the accuracy of evaluating the efficacy of TACE treatment for invasive liver cancer.The corrected ETV and its reduction rate can serve as independent indicators for predicting patient prognosis,providing important reference for developing individualized treatment strategies.
文摘BACKGROUND Obstructed defecation syndrome(ODS)is a subtype of constipation that is consi-dered one of the major pelvic floor dysfunctions affecting the aging population,particularly women over 50 seeking medical care.The condition is characterized by the urge to defecate but an impaired ability to expel the fecal bolus.ODS is associated with various anorectal abnormalities,which are not always apparent during a standard physical examination,requiring specialized imaging techniques for proper diagnosis.AIM To study the distribution of causes of ODS in patients with chronic constipation by magnetic resonance defecography(MRD).METHODS This observational study evaluated the causes of ODS in 57 patients with chronic constipation who presented to Bangabandhu Sheikh Mujib Medical University between July 2020 and June 2021.After obtaining institutional review board approval and informed consent,patients underwent history taking,physical exams,and relevant investigations.ODS was diagnosed using Rome III criteria,with colonoscopy ruling out organic causes.Standard MRD was performed in different phases,and images were analyzed by expert radiologists and reported in a stan-dardized format.RESULTS Pelvic floor descent and anorectal junction descent were the most frequent findings,each present in 94.7%of cases.Rectocele was observed in 78.9%of patients,while vaginal or uterine prolapse was seen in 59.4%of females.Less common abnormalities included paradoxical contraction(7%),and there were no cases of sigmoidocele.Functional measurements showed significant differences in pelvic floor dynamics between rest and defecation,particularly in the H-line,M-line,and descent of pelvic organs(P<0.05).CONCLUSION Pelvic floor descent and anorectal descent were the most common findings in patients suffering from ODS,fo-llowed by rectocele.Younger females(<30 years)were most affected.
