The material identification is a pressing requirement for the sensitive security applications. Dual-energy X-ray computer tomography (DXCT) has been investigated for material identification in the medical and security...The material identification is a pressing requirement for the sensitive security applications. Dual-energy X-ray computer tomography (DXCT) has been investigated for material identification in the medical and security fields. It requires two tomographic images at sufficiently different energies. To discriminate dangerous materials of light elements such as plastic bombs in luggage, it is needed to measure accurately with several tens of kilo electron volts where such materials exhibit significant spectral differences. However, CT images in that energy region often include artifacts from beam hardening. To reduce these artifacts, a novel reconstruction method has been investigated. It is an extension of the Al-gebraic Reconstruction Technique and Total Variation (ART-TV) method that reduces the artifacts in a lower-energy CT image by referencing it to an image obtained at higher energy. The CT image of a titanium sample was recon-structed using this method in order to demonstrate the artifact reduction capability.展开更多
The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an ...The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an X-ray computed tomography(X-ray CT)was used,i e,the tomography system of Zeiss Xradia 510 versa.The results indicate that X-CT can monitor the development process and distribution characteristics of the internal cracks of cement pastes under ESA with attack time.In addition,the C3A content in the cement significantly affects the damage mode of cement paste specimens during sulfate erosion.The damage of ordinary Portland cement(OPC)pastes subjected to sulfate attack with high C3A content are severe,while the damage of sulfate resistant Portland cement(SRPC)pastes is much smaller than that of OPC pastes.Furthermore,a quadratic function describes the correlation between the crack volume fraction and development depth for two cement pastes immermed in sulfate solution.展开更多
Purpose To propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized X-rays.Methods Monte Carlo simulations were adopted to demonstrate the feasibility of th...Purpose To propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized X-rays.Methods Monte Carlo simulations were adopted to demonstrate the feasibility of the proposed method.In the simulations,the phantom is a polytetrafluoroethylene cylinder inside which are cylindrical columns containing aluminum,water,and gold(Au)-loaded water solutions with Au concentrations ranging between 0.5 and 4.0 wt%,and a parallel-hole collimator imaging geometry was adopted.The light source was modeled based on a Thomson scattering X-ray source.The phantom images for both imaging modalities were reconstructed using a maximumlikelihood expectation maximization algorithm.Results Both the X-ray fluorescence computed tomography(XFCT)and Compton scattering computed tomography(CSCT)images of the phantom were accurately reconstructed.A similar attenuation contrast problem for the different cylindrical columns in the phantom can be resolved in the XFCT and CSCT images.The interplay between XFCT and CSCT was analyzed,and the contrast-to-noise ratio(CNR)of the reconstruction was improved by correcting for the mutual influence between the two imaging modalities.Compared with K-edge subtraction imaging,XFCT exhibits a CNR advantage for the phantom.Conclusion Simultaneous XFCT and CSCT can be realized by using linearly polarized X-rays.The synergy between the two imaging modalities would have an important application in cancer radiation therapy.展开更多
Different sedimentary zones in coral reefs lead to significant anisotropy in the pore structure of coral reef limestone(CRL),making it difficult to study mechanical behaviors.With X-ray computed tomography(CT),112 CRL...Different sedimentary zones in coral reefs lead to significant anisotropy in the pore structure of coral reef limestone(CRL),making it difficult to study mechanical behaviors.With X-ray computed tomography(CT),112 CRL samples were utilized for training the support vector machine(SVM)-,random forest(RF)-,and back propagation neural network(BPNN)-based models,respectively.Simultaneously,the machine learning model was embedded into genetic algorithm(GA)for parameter optimization to effectively predict uniaxial compressive strength(UCS)of CRL.Results indicate that the BPNN model with five hidden layers presents the best training effect in the data set of CRL.The SVM-based model shows a tendency to overfitting in the training set and poor generalization ability in the testing set.The RF-based model is suitable for training CRL samples with large data.Analysis of Pearson correlation coefficient matrix and the percentage increment method of performance metrics shows that the dry density,pore structure,and porosity of CRL are strongly correlated to UCS.However,the P-wave velocity is almost uncorrelated to the UCS,which is significantly distinct from the law for homogenous geomaterials.In addition,the pore tensor proposed in this paper can effectively reflect the pore structure of coral framework limestone(CFL)and coral boulder limestone(CBL),realizing the quantitative characterization of the heterogeneity and anisotropy of pore.The pore tensor provides a feasible idea to establish the relationship between pore structure and mechanical behavior of CRL.展开更多
During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a rest...During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.展开更多
AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR),and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA scree...AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR),and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA screening indicators to detect concurrent DR at an early stage.METHODS:A total of 200 patients who treated in the ophthalmology department of the Seventh Affiliated Hospital,Sun Yat-sen University from 2022 to 2023 were included,including 95 first-diagnosed DR patients and 105 patients without DR,and all patients underwent OCTA examination and a collection of demographics and renal function parameters.After a quality check,automated measurements of the foveal avascular zone area,vessel density(VD),and perfusion density(PD)of both 3 mm×3 mm and 6 mm×6 mm windows were obtained.RESULTS:Using random forest and multivariate Logistic regression methods,we developed a diagnostic model for DR based on 12 variables(age,FBG,SBP,DBP,HbA1c,ALT,ALP,urea/Scr,DM duration,HUA,DN,and CMT).Adding specific OCTA parameters enhanced the efficacy of the existing diagnostic model for DR(outer vessel density in 6 mm×6 mm window,AUC=0.837 vs 0.819,P=0.03).In the study of DN patients,the parameters in the 6 mm×6 mm window improved the diagnostic efficacy of DR(inner VD;outer VD;full VD;outer PD;full PD).CONCLUSION:The outer VD in the 6 mm×6 mm window can enhance the efficacy of the traditional DR diagnostic model.Meanwhile,compared with the 3 mm×3 mm window,the microvascular parameters in the 6 mm×6 mm window focusing on DN patients can be more sensitive to diagnosing the occurrence of DR.展开更多
Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic equator.EPBs most commonly occur after sunset during the equinox months,although they can also be observed during other s...Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic equator.EPBs most commonly occur after sunset during the equinox months,although they can also be observed during other seasons.The phenomenon significantly disrupts radio wave signals essential to communication and navigation systems.The national network of Global Navigation Satellite System(GNSS)receivers in Indonesia(>30°longitudinal range)provides an opportunity for detailed EPB studies.To explore this,we conducted preliminary 3D tomography of total electron content(TEC)data captured by GNSS receivers following a geomagnetic storm on December 3,2023,when at least four EPB clusters occurred in the Southeast Asian sector.TEC and extracted TEC depletion with a 120-minute running average were then used as inputs for a 3D tomography program.Their 2D spatial distribution consistently captured the four EPB clusters over time.These tomography results were validated through a classical checkerboard test and comparisons with other ionospheric data sources,such as the Global Ionospheric Map(GIM)and International Reference Ionosphere(IRI)profile.Validation of the results demonstrates the capability of the Indonesian GNSS network to measure peak ionospheric density.These findings highlight the potential for future three-dimensional research of plasma bubbles in low-latitude regions using existing GNSS networks,with extensive longitudinal coverage.展开更多
BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significan...BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significant challenge due to its limited accessibility through conventional endoscopic methods.AIM To establish a noninvasive radiomic model based on computed tomography enterography(CTE)for MH assessment in SBCD patients.METHODS Seventy-three patients diagnosed with SBCD were included and divided into a training cohort(n=55)and a test cohort(n=18).Radiomic features were obtained from CTE images to establish a radiomic model.Patient demographics were analysed to establish a clinical model.A radiomic-clinical nomogram was constructed by combining significant clinical and radiomic features.The diagnostic efficacy and clinical benefit were evaluated via receiver operating characteristic(ROC)curve analysis and decision curve analysis(DCA),respectively.RESULTS Of the 73 patients enrolled,25 patients achieved MH.The radiomic-clinical nomogram had an area under the ROC curve of 0.961(95%confidence interval:0.886-1.000)in the training cohort and 0.958(0.877-1.000)in the test cohort and provided superior clinical benefit to either the clinical or radiomic models alone,as demonstrated by DCA.CONCLUSION These results indicate that the CTE-based radiomic-clinical nomogram is a promising imaging biomarker for MH and serves as a potential noninvasive alternative to enteroscopy for MH assessment in SBCD patients.展开更多
Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular imaging.Traditional CT systems employ energy-integrating detectors that convert X-ray photons into visible ligh...Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular imaging.Traditional CT systems employ energy-integrating detectors that convert X-ray photons into visible light,whereas PCCT utilizes photon-counting detectors that directly transform X-ray photons into electric signals.This direct conversion allows photon-counting detectors to sort photons into discrete energy levels,thereby enhancing image quality through superior noise reduction,improved spatial and contrast resolution,and reduced artifacts.In pediatric applications,PCCT offers substantial benefits,including lower radiation doses,which may help reduce the risk of malignancy in pediatric patients,with perhaps greater potential to benefit those with repeated exposure from a young age.Enhanced spatial resolution facilitates better visualization of small structures,vital for diagnosing congenital heart defects.Additionally,PCCT’s spectral capabilities improve tissue characterization and enable the creation of virtual monoenergetic images,which enhance soft-tissue contrast and potentially reduce contrast media doses.Initial clinical results indicate that PCCT provides superior image quality and diagnostic accuracy compared to conven-tional CT,particularly in challenging pediatric cardiovascular cases.As PCCT technology matures,further research and standardized protocols will be essential to fully integrate it into pediatric imaging practices,ensuring optimized diagnostic outcomes and patient safety.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
Nanomaterials have greatly received interest in various fields due to their excellent activity,typically attributed to their nanoscale physical and chemical properties.Transmission electron microscopy(TEM)as a powerfu...Nanomaterials have greatly received interest in various fields due to their excellent activity,typically attributed to their nanoscale physical and chemical properties.Transmission electron microscopy(TEM)as a powerful tool for characterizing nanomaterials can offer microscopic information with high spatial resolution.However,TEM faces challenges in obtaining information along the electron beam direction(Z direction),which limits its ability to explore the unique characteristics of nanomaterials on a three-dimensional(3D)scale.Electron tomography(ET)is an advanced imaging technique that allows for the visualization of 3D structures of nanomaterials.When combined with energy-dispersive X-ray spectroscopy(EDS)or electron energy loss spectroscopy(EELS),it enables researchers to reveal chemical changes in three dimensions,enhancing the understanding of the complex mechanisms underlying changes in chemical properties.This review summarizes and discusses the recent advancements in EDS/EELS(chemical-sensitive)ET imaging techniques,including the traditional reconstruction method,deep learning-based method,and multi-modal method,which provide detailed processes of reconstruction to facilitate the understanding of how they work for related researchers.Moreover,several successful applications are presented to show the capabilities of chemical-sensitive ET in diverse fields.Finally,the existing challenges and solutions are discussed to propel the development of ET imaging techniques.展开更多
The lattice parameter,measured with sufficient accuracy,can be utilized to evaluate the quality of single crystals and to determine the equation of state for materials.We propose an iterative method for obtaining more...The lattice parameter,measured with sufficient accuracy,can be utilized to evaluate the quality of single crystals and to determine the equation of state for materials.We propose an iterative method for obtaining more precise lattice parameters using the interaction points for the pseudo-Kossel pattern obtained from laser-induced X-ray diffraction(XRD).This method has been validated by the analysis of an XRD experiment conducted on iron single crystals.Furthermore,the method was used to calculate the compression ratio and rotated angle of an LiF sample under high pressure loading.This technique provides a robust tool for in-situ characterization of structural changes in single crystals under extreme conditions.It has significant implications for studying the equation of state and phase transitions.展开更多
Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism....Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders.展开更多
A 100-channel double-foil soft X-ray array imaging(DSXAI)diagnostic system has been developed for the HL-2A tokamak to obtain tomographic bremsstrahlung emissivity and electron temperature(T_(e)).This system employs a...A 100-channel double-foil soft X-ray array imaging(DSXAI)diagnostic system has been developed for the HL-2A tokamak to obtain tomographic bremsstrahlung emissivity and electron temperature(T_(e)).This system employs a double-foil technique to determine T_(e) by comparing the soft X-ray(SXR)emissivities from the same plasma location through two beryllium(Be)foils of differing thickness.The DSXAI system comprises five photocameras mounted at two different poloidal cross-sections,separated toroidally by 15°,allowing for three distinct poloidal viewing angles.Each photocamera features 20 channels,offering a temporal resolution of approximately 4μs and a spatial resolution of about 8 cm,with no channel overlap.Each photocamera contains two identical optical systems,each defined by an aperture slit and a photodiode array.The double-foil configuration is realized by placing these two optical systems,each with a different Be foil,in close proximity.Initial experimental results demonstrate that the DSXAI diagnostic system performs well,successfully reconstructing 2-dimensional(2D)tomographic SXR emissivity and T_(e) on the HL-2A tokamak.This study provides valuable insights for the future implementation of similar diagnostic systems on fusion reactors like ITER.展开更多
Deep learning(DL)-based image reconstruction methods have garnered increasing interest in the last few years.Numerous studies demonstrate that DL-based reconstruction methods function admirably in optical tomographic ...Deep learning(DL)-based image reconstruction methods have garnered increasing interest in the last few years.Numerous studies demonstrate that DL-based reconstruction methods function admirably in optical tomographic imaging techniques,such as bioluminescence tomography(BLT).Nevertheless,nearly every existing DL-based method utilizes an explicit neural representation for the reconstruction problem,which either consumes much memory space or requires various complicated computations.In this paper,we present a neural field(NF)-based image reconstruction scheme for BLT that uses an implicit neural representation.The proposed NFbased method establishes a transformation between the coordinate of an arbitrary spatial point and the source value of the point with a relatively light-weight multilayer perceptron,which has remarkable computational efficiency.Another simple neural network composed of two fully connected layers and a 1D convolutional layer is used to generate the neural features.Results of simulations and experiments show that the proposed NF-based method has similar performance to the photon density complement network and the two-stage network,while consuming fewer floating point operations with fewer model parameters.展开更多
BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are ne...BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are necessary.However,due to differences in race and sex,people’s body shapes vary.According to European guidelines,the patch should measure 10 cm×15 cm.If any part of the MPO is dissected,injury to the nerves,vascular network,or organs may occur during surgery,thereby leading to inguinal discomfort,pain,and seroma formation after surgery.Therefore,accurate localization and measurement of the boundary of the MPO are crucial for selecting the optimal patch for inguinal hernia repair.AIM To compare the size of the MPO measured on three-dimensional multislice spiral computed tomography(CT)with that measured via laparoscopy and explore the relevant factors influencing the size of the MPO.METHODS Clinical data from 74 patients who underwent laparoscopic tension-free inguinal hernia repair at the General Surgery Department of the First Affiliated Hospital of Anhui University of Science and Technology between September 2022 and July 2024 were collected and analyzed retrospectively.Transabdominal preperitoneal was performed.Sixty-four males and 10 females,with an average age of 58.30±12.32 years,were included.The clinical data of the patients were collected.The boundary of the MPO was measured on three-dimensional CT images before surgery and then again during transabdominal preperitoneal.All the preoperative and intraoperative data were analyzed via paired t-tests.A t-test was used for comparisons of age,body mass index,and sex between the groups.In the comparative analysis,a P value less than 0.05 indicated a significant difference.RESULTS The boundaries of the MPO on 3-dimensional CT images measured 7.05±0.47 cm and 6.27±0.61 cm,and the area of the MPO was 19.54±3.33 cm^(2).The boundaries of the MPO during surgery were 7.18±0.51 cm and 6.17±0.40 cm.The errors were not statistically significant.However,the intraoperative BD(the width of the MPO,P=0.024,P<0.05)and preoperative AC(the length of the MPO,P=0.045,P<0.05)significantly differed according to sex.The AC and BD measurements before and during surgery were not significantly different according to age,body mass index,hernia side or hernia type(P>0.05).CONCLUSION The application of this technology can aid in determining the most appropriate dissection range and patch size.展开更多
BACKGROUND Gastric schwannoma(GS)is often misdiagnosed as gastrointestinal stromal tumors due to the high incidence of the latter.However,these two types differ significantly in pathology and biological behavior.AIM T...BACKGROUND Gastric schwannoma(GS)is often misdiagnosed as gastrointestinal stromal tumors due to the high incidence of the latter.However,these two types differ significantly in pathology and biological behavior.AIM To evaluate the computed tomography characteristics of GS and provide insights into its accurate diagnosis.METHODS Twenty-three cases of GS confirmed between January 2011 and December 2023 were assessed clinically and radiologically.Imaging characteristics,including tumor location,size,contour,ulceration,growth pattern,enhancement degree and pattern,cystic change,calcification,and perigastric lymph nodes(PLNs),were reviewed by two experienced radiologists.RESULTS Our sample included 18 females and 5 males,with a median age of 54.7 years.A total of 39.1%of cases were asymptomatic.GSs appeared as oval and well-defined submucosal tumors,with exophytic(43.5%)or mixed(endoluminal+exophytic;43.5%)growth patterns.The tumors were primarily located in the gastric body(78.3%).Ulcerations were observed in 8 cases(34.5%),and PLNs were observed in 15 cases(65%).The average degree of enhancement was 48.3 Hounsfield units.Twenty cases(87%)showed peak enhancement in the delayed phase.Most GSs were homogeneous,while cystic change(13.0%)and calcification(17.4%)were rare.CONCLUSION GS predominantly showed gradual homogenous enhancement with peak enhancement in the delayed phase.PLNs around GS are helpful in differentiating GS from other gastric submucosal tumors.展开更多
BACKGROUND Effective management of liver abscess depends on timely drainage,which is influenced by the liquefaction degree.Identifying predictive factors is crucial for guiding clinical decisions.AIM To investigate th...BACKGROUND Effective management of liver abscess depends on timely drainage,which is influenced by the liquefaction degree.Identifying predictive factors is crucial for guiding clinical decisions.AIM To investigate the predictive factors of liver abscess liquefaction and develop a predictive model to guide optimal timing of percutaneous drainage.METHODS This retrospective study included 110 patients with pyogenic liver abscesses who underwent percutaneous catheter drainage.Patients were divided into a poor liquefaction group(n=28)and a well liquefaction group(n=82)based on the ratio of postoperative 24-hour drainage volume to abscess volume,using a cutoff value of 0.3.Clinical characteristics,laboratory indicators,and computed tomography imaging features were compared.A predictive model was constructed using logistic regression and evaluated using receiver operating characteristic curves and five-fold cross-validation.RESULTS Independent predictive factors for good liquefaction included the absence of diabetes[odds ratio(OR)=0.339,P=0.044],absence of pneumonia(OR=0.218,P=0.013),left-lobe abscess location(OR=4.293,P=0.041),cystic features(OR=5.104,P=0.025),and elevated preoperative serum alanine aminotransferase(ALT)levels(OR=1.013,P=0.041).The logistic regression model based on these factors demonstrated an area under the curve of 0.814,with a sensitivity of 90.24%and specificity of 67.86%.Five-fold cross-validation yielded an average accuracy of 83.61%and a kappa coefficient of 0.5209.CONCLUSION Pneumonia,diabetes,abscess location,abscess composition,and preoperative serum ALT levels are significant predictors of liver abscess liquefaction.The model can guide clinical decision-making.展开更多
Computed tomography(CT)can inspect the internal structure of concrete with high resolution,but improving the accuracy of measurements remains a key challenge due to the reliance on complex image processing and signifi...Computed tomography(CT)can inspect the internal structure of concrete with high resolution,but improving the accuracy of measurements remains a key challenge due to the reliance on complex image processing and significant manual intervention.This study aims to optimize CT scanning parameters to enhance the accuracy of measuring crack widths and rebar volumes in reinforced concrete.Nine sets of specimens,each with varying rebar diameters and concrete cover thicknesses,were scanned before and after corrosion using an Optima CT scanner,followed by three-dimensional reconstructions using Avizo software.The effects of threshold values and“Erosion”coefficients on measurement accuracy were evaluated.The results demonstrated that an optimal lower threshold of 2950,combined with an‘Erosion’coefficient of 6,effectively limits the measurement error of rebar volumes to within 1%.The optimal threshold for measuring crack widths was influenced by the crack width,rebar diameter,and concrete cover thickness.Additionally,an optimized formula for determining crack measurement thresholds was proposed.This study significantly improves the accuracy of CT-based non-destructive testing(NDT)techniques,providing valuable insights for structural health monitoring(SHM).展开更多
BACKGROUND Migraine has been proposed as a potential contributing factor to ischemic complications involving the retina and optic nerve.Ophthalmic disorders connected with migraine encompass occlusions of the branch a...BACKGROUND Migraine has been proposed as a potential contributing factor to ischemic complications involving the retina and optic nerve.Ophthalmic disorders connected with migraine encompass occlusions of the branch and central retinal arteries and veins,alongside anterior and posterior ischemic optic neuropathy.With the advent of optical coherence tomography angiography(OCTA),it is easy to identify these macular subclinical microvascular and structural changes.AIM To evaluate macular and peripapillary structural and microvasculature changes in patients with migraine with aura(MA),migraine without aura(MW),and healthy control(HC)participants using OCTA.METHODS In this observational cross-sectional study,we studied a total of 100 eyes:(1)32 eyes of 16 patients with MA;(2)36 eyes of 18 patients with MW,recruited based on the International Classification of Headache Disorders;and(3)32 eyes of 16 age and sex-matched healthy participants.Foveal flux,foveal avascular zone(FAZ),peripapillary flux obtained from OCTA,and foveal and peripapillary ganglion cell layer(GCL)thickness calculated via optical coherence tomography were compared among the groups.RESULTS The mean FAZ area measured in patients with MA and MW was significantly larger than that in the control participants(P=0.002).However,there was no significant difference between the FAZ of the MA and MW groups.Macular perfusion in the superficial capillary plexus in patients with MA was significantly lower compared to MW(P=0.0018)and HCs(P=0.002).There was also significant thinning of the GCL in patients with MA and MW(P=0.001)compared to HCs.However,there was no significant difference in temporal GCL thickness between the MA and MW groups.CONCLUSION Significant changes have been found in structural and microvascular parameters in patients with migraines compared with HCs.OCTA can serve as a valuable non-invasive imaging technique for identifying microcirculatory disturbances,aiding in better understanding the pathogenesis of different types of migraine and establishing their link with other ischemic retinal and systemic pathologies.展开更多
文摘The material identification is a pressing requirement for the sensitive security applications. Dual-energy X-ray computer tomography (DXCT) has been investigated for material identification in the medical and security fields. It requires two tomographic images at sufficiently different energies. To discriminate dangerous materials of light elements such as plastic bombs in luggage, it is needed to measure accurately with several tens of kilo electron volts where such materials exhibit significant spectral differences. However, CT images in that energy region often include artifacts from beam hardening. To reduce these artifacts, a novel reconstruction method has been investigated. It is an extension of the Al-gebraic Reconstruction Technique and Total Variation (ART-TV) method that reduces the artifacts in a lower-energy CT image by referencing it to an image obtained at higher energy. The CT image of a titanium sample was recon-structed using this method in order to demonstrate the artifact reduction capability.
基金Funded by Chinese National Natural Science Foundation of China(No.U2006224)。
文摘The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an X-ray computed tomography(X-ray CT)was used,i e,the tomography system of Zeiss Xradia 510 versa.The results indicate that X-CT can monitor the development process and distribution characteristics of the internal cracks of cement pastes under ESA with attack time.In addition,the C3A content in the cement significantly affects the damage mode of cement paste specimens during sulfate erosion.The damage of ordinary Portland cement(OPC)pastes subjected to sulfate attack with high C3A content are severe,while the damage of sulfate resistant Portland cement(SRPC)pastes is much smaller than that of OPC pastes.Furthermore,a quadratic function describes the correlation between the crack volume fraction and development depth for two cement pastes immermed in sulfate solution.
基金supported by the National Natural Science Foundation of China(Nos.12375157,12027902,and 11905011)。
文摘Purpose To propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized X-rays.Methods Monte Carlo simulations were adopted to demonstrate the feasibility of the proposed method.In the simulations,the phantom is a polytetrafluoroethylene cylinder inside which are cylindrical columns containing aluminum,water,and gold(Au)-loaded water solutions with Au concentrations ranging between 0.5 and 4.0 wt%,and a parallel-hole collimator imaging geometry was adopted.The light source was modeled based on a Thomson scattering X-ray source.The phantom images for both imaging modalities were reconstructed using a maximumlikelihood expectation maximization algorithm.Results Both the X-ray fluorescence computed tomography(XFCT)and Compton scattering computed tomography(CSCT)images of the phantom were accurately reconstructed.A similar attenuation contrast problem for the different cylindrical columns in the phantom can be resolved in the XFCT and CSCT images.The interplay between XFCT and CSCT was analyzed,and the contrast-to-noise ratio(CNR)of the reconstruction was improved by correcting for the mutual influence between the two imaging modalities.Compared with K-edge subtraction imaging,XFCT exhibits a CNR advantage for the phantom.Conclusion Simultaneous XFCT and CSCT can be realized by using linearly polarized X-rays.The synergy between the two imaging modalities would have an important application in cancer radiation therapy.
基金supported by the National Natural Science Foundation of China(Grant Nos.41877267 and 41877260)the Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA13010201).
文摘Different sedimentary zones in coral reefs lead to significant anisotropy in the pore structure of coral reef limestone(CRL),making it difficult to study mechanical behaviors.With X-ray computed tomography(CT),112 CRL samples were utilized for training the support vector machine(SVM)-,random forest(RF)-,and back propagation neural network(BPNN)-based models,respectively.Simultaneously,the machine learning model was embedded into genetic algorithm(GA)for parameter optimization to effectively predict uniaxial compressive strength(UCS)of CRL.Results indicate that the BPNN model with five hidden layers presents the best training effect in the data set of CRL.The SVM-based model shows a tendency to overfitting in the training set and poor generalization ability in the testing set.The RF-based model is suitable for training CRL samples with large data.Analysis of Pearson correlation coefficient matrix and the percentage increment method of performance metrics shows that the dry density,pore structure,and porosity of CRL are strongly correlated to UCS.However,the P-wave velocity is almost uncorrelated to the UCS,which is significantly distinct from the law for homogenous geomaterials.In addition,the pore tensor proposed in this paper can effectively reflect the pore structure of coral framework limestone(CFL)and coral boulder limestone(CBL),realizing the quantitative characterization of the heterogeneity and anisotropy of pore.The pore tensor provides a feasible idea to establish the relationship between pore structure and mechanical behavior of CRL.
基金financially supported by the National Natural Science Foundation of China(Nos.52274315 and 52374320)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-22-011A1 and FRF-DF22-16)。
文摘During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.
文摘AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR),and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA screening indicators to detect concurrent DR at an early stage.METHODS:A total of 200 patients who treated in the ophthalmology department of the Seventh Affiliated Hospital,Sun Yat-sen University from 2022 to 2023 were included,including 95 first-diagnosed DR patients and 105 patients without DR,and all patients underwent OCTA examination and a collection of demographics and renal function parameters.After a quality check,automated measurements of the foveal avascular zone area,vessel density(VD),and perfusion density(PD)of both 3 mm×3 mm and 6 mm×6 mm windows were obtained.RESULTS:Using random forest and multivariate Logistic regression methods,we developed a diagnostic model for DR based on 12 variables(age,FBG,SBP,DBP,HbA1c,ALT,ALP,urea/Scr,DM duration,HUA,DN,and CMT).Adding specific OCTA parameters enhanced the efficacy of the existing diagnostic model for DR(outer vessel density in 6 mm×6 mm window,AUC=0.837 vs 0.819,P=0.03).In the study of DN patients,the parameters in the 6 mm×6 mm window improved the diagnostic efficacy of DR(inner VD;outer VD;full VD;outer PD;full PD).CONCLUSION:The outer VD in the 6 mm×6 mm window can enhance the efficacy of the traditional DR diagnostic model.Meanwhile,compared with the 3 mm×3 mm window,the microvascular parameters in the 6 mm×6 mm window focusing on DN patients can be more sensitive to diagnosing the occurrence of DR.
基金the National Institute of Information and Communication Technology International Exchange Program 2024−2025(No.2024−007)for their invaluable support in this research.3D tomography software is available at Prof.Kosuke Heki’s(Hokkaido University,Japan)personal homepage(https://www.ep.sci.hokudai.ac.jp/~heki/software.htm).support from the 2024 Japan Student Services Organization Research Follow-up Fellowship for a 90-day research visit at the Institute for Space−Earth Environmental Research,Nagoya University,Japan.PA also acknowledges the support received from Telkom University under the“Skema Penelitian Terapan Periode I Tahun Anggaran 2024”,and the Memorandum of Understanding for Research Collaboration on Regional Ionospheric Observation(No:092/SAM3/TE-DEK/2021).
文摘Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic equator.EPBs most commonly occur after sunset during the equinox months,although they can also be observed during other seasons.The phenomenon significantly disrupts radio wave signals essential to communication and navigation systems.The national network of Global Navigation Satellite System(GNSS)receivers in Indonesia(>30°longitudinal range)provides an opportunity for detailed EPB studies.To explore this,we conducted preliminary 3D tomography of total electron content(TEC)data captured by GNSS receivers following a geomagnetic storm on December 3,2023,when at least four EPB clusters occurred in the Southeast Asian sector.TEC and extracted TEC depletion with a 120-minute running average were then used as inputs for a 3D tomography program.Their 2D spatial distribution consistently captured the four EPB clusters over time.These tomography results were validated through a classical checkerboard test and comparisons with other ionospheric data sources,such as the Global Ionospheric Map(GIM)and International Reference Ionosphere(IRI)profile.Validation of the results demonstrates the capability of the Indonesian GNSS network to measure peak ionospheric density.These findings highlight the potential for future three-dimensional research of plasma bubbles in low-latitude regions using existing GNSS networks,with extensive longitudinal coverage.
基金Supported by Natural Science Foundation of Anhui Medical University,No.2023xkj130.
文摘BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significant challenge due to its limited accessibility through conventional endoscopic methods.AIM To establish a noninvasive radiomic model based on computed tomography enterography(CTE)for MH assessment in SBCD patients.METHODS Seventy-three patients diagnosed with SBCD were included and divided into a training cohort(n=55)and a test cohort(n=18).Radiomic features were obtained from CTE images to establish a radiomic model.Patient demographics were analysed to establish a clinical model.A radiomic-clinical nomogram was constructed by combining significant clinical and radiomic features.The diagnostic efficacy and clinical benefit were evaluated via receiver operating characteristic(ROC)curve analysis and decision curve analysis(DCA),respectively.RESULTS Of the 73 patients enrolled,25 patients achieved MH.The radiomic-clinical nomogram had an area under the ROC curve of 0.961(95%confidence interval:0.886-1.000)in the training cohort and 0.958(0.877-1.000)in the test cohort and provided superior clinical benefit to either the clinical or radiomic models alone,as demonstrated by DCA.CONCLUSION These results indicate that the CTE-based radiomic-clinical nomogram is a promising imaging biomarker for MH and serves as a potential noninvasive alternative to enteroscopy for MH assessment in SBCD patients.
文摘Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular imaging.Traditional CT systems employ energy-integrating detectors that convert X-ray photons into visible light,whereas PCCT utilizes photon-counting detectors that directly transform X-ray photons into electric signals.This direct conversion allows photon-counting detectors to sort photons into discrete energy levels,thereby enhancing image quality through superior noise reduction,improved spatial and contrast resolution,and reduced artifacts.In pediatric applications,PCCT offers substantial benefits,including lower radiation doses,which may help reduce the risk of malignancy in pediatric patients,with perhaps greater potential to benefit those with repeated exposure from a young age.Enhanced spatial resolution facilitates better visualization of small structures,vital for diagnosing congenital heart defects.Additionally,PCCT’s spectral capabilities improve tissue characterization and enable the creation of virtual monoenergetic images,which enhance soft-tissue contrast and potentially reduce contrast media doses.Initial clinical results indicate that PCCT provides superior image quality and diagnostic accuracy compared to conven-tional CT,particularly in challenging pediatric cardiovascular cases.As PCCT technology matures,further research and standardized protocols will be essential to fully integrate it into pediatric imaging practices,ensuring optimized diagnostic outcomes and patient safety.
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 National Key Research and Development Program of China(No.2022YFA1505700)the National Natural Science Foundation of China(Nos.22475214,22205232)+2 种基金the Talent Plan of Shanghai Branch,Chinese Academy of Sciences(No.CASSHB-QNPD-2023-020)the Natural Science Foundation of Fujian Province,China(No.2023J06044)the Self-deployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences(Nos.CXZX-2022-JQ06,CXZX-2022-GH03).
文摘Nanomaterials have greatly received interest in various fields due to their excellent activity,typically attributed to their nanoscale physical and chemical properties.Transmission electron microscopy(TEM)as a powerful tool for characterizing nanomaterials can offer microscopic information with high spatial resolution.However,TEM faces challenges in obtaining information along the electron beam direction(Z direction),which limits its ability to explore the unique characteristics of nanomaterials on a three-dimensional(3D)scale.Electron tomography(ET)is an advanced imaging technique that allows for the visualization of 3D structures of nanomaterials.When combined with energy-dispersive X-ray spectroscopy(EDS)or electron energy loss spectroscopy(EELS),it enables researchers to reveal chemical changes in three dimensions,enhancing the understanding of the complex mechanisms underlying changes in chemical properties.This review summarizes and discusses the recent advancements in EDS/EELS(chemical-sensitive)ET imaging techniques,including the traditional reconstruction method,deep learning-based method,and multi-modal method,which provide detailed processes of reconstruction to facilitate the understanding of how they work for related researchers.Moreover,several successful applications are presented to show the capabilities of chemical-sensitive ET in diverse fields.Finally,the existing challenges and solutions are discussed to propel the development of ET imaging techniques.
基金National Natural Science Foundation of China(12102410)Fund of National Key Laboratory of Shock Wave and Detonation Physics(JCKYS2022212005)。
文摘The lattice parameter,measured with sufficient accuracy,can be utilized to evaluate the quality of single crystals and to determine the equation of state for materials.We propose an iterative method for obtaining more precise lattice parameters using the interaction points for the pseudo-Kossel pattern obtained from laser-induced X-ray diffraction(XRD).This method has been validated by the analysis of an XRD experiment conducted on iron single crystals.Furthermore,the method was used to calculate the compression ratio and rotated angle of an LiF sample under high pressure loading.This technique provides a robust tool for in-situ characterization of structural changes in single crystals under extreme conditions.It has significant implications for studying the equation of state and phase transitions.
基金supported by the Research Project of the Shanghai Health Commission,No.2020YJZX0111(to CZ)the National Natural Science Foundation of China,Nos.82021002(to CZ),82272039(to CZ),82171252(to FL)+1 种基金a grant from the National Health Commission of People’s Republic of China(PRC),No.Pro20211231084249000238(to JW)Medical Innovation Research Project of Shanghai Science and Technology Commission,No.21Y11903300(to JG).
文摘Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders.
基金supported by the National Magnetic Confinement Fusion Science Program of China (Nos.2022YFE03100004,2017YFE0301700,2017YFE0301701 and 2022YFE03060003)National Natural Science Foundation of China (Nos.12375226,12175227,11875255 and 11975231)+2 种基金the China Postdoctoral Science Foundation (No.2022M723066)the Fundamental Research Funds for the Central Universitiesthe Collaborative Innovation Program of Hefei Science Center,CAS (No.2022HSCCIP022)。
文摘A 100-channel double-foil soft X-ray array imaging(DSXAI)diagnostic system has been developed for the HL-2A tokamak to obtain tomographic bremsstrahlung emissivity and electron temperature(T_(e)).This system employs a double-foil technique to determine T_(e) by comparing the soft X-ray(SXR)emissivities from the same plasma location through two beryllium(Be)foils of differing thickness.The DSXAI system comprises five photocameras mounted at two different poloidal cross-sections,separated toroidally by 15°,allowing for three distinct poloidal viewing angles.Each photocamera features 20 channels,offering a temporal resolution of approximately 4μs and a spatial resolution of about 8 cm,with no channel overlap.Each photocamera contains two identical optical systems,each defined by an aperture slit and a photodiode array.The double-foil configuration is realized by placing these two optical systems,each with a different Be foil,in close proximity.Initial experimental results demonstrate that the DSXAI diagnostic system performs well,successfully reconstructing 2-dimensional(2D)tomographic SXR emissivity and T_(e) on the HL-2A tokamak.This study provides valuable insights for the future implementation of similar diagnostic systems on fusion reactors like ITER.
基金supported in part by the National Natural Science Foundation of China(62101278,62001379,62271023)Beijing Natural Science Foundation(7242269).
文摘Deep learning(DL)-based image reconstruction methods have garnered increasing interest in the last few years.Numerous studies demonstrate that DL-based reconstruction methods function admirably in optical tomographic imaging techniques,such as bioluminescence tomography(BLT).Nevertheless,nearly every existing DL-based method utilizes an explicit neural representation for the reconstruction problem,which either consumes much memory space or requires various complicated computations.In this paper,we present a neural field(NF)-based image reconstruction scheme for BLT that uses an implicit neural representation.The proposed NFbased method establishes a transformation between the coordinate of an arbitrary spatial point and the source value of the point with a relatively light-weight multilayer perceptron,which has remarkable computational efficiency.Another simple neural network composed of two fully connected layers and a 1D convolutional layer is used to generate the neural features.Results of simulations and experiments show that the proposed NF-based method has similar performance to the photon density complement network and the two-stage network,while consuming fewer floating point operations with fewer model parameters.
基金Supported by the 2022 Provincial Quality Engineering Project for Higher Education Institutions,No.2022sx031the 2023 Provincial Quality Engineering Project for Higher Education Institutions,No.2023jyxm1071.
文摘BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are necessary.However,due to differences in race and sex,people’s body shapes vary.According to European guidelines,the patch should measure 10 cm×15 cm.If any part of the MPO is dissected,injury to the nerves,vascular network,or organs may occur during surgery,thereby leading to inguinal discomfort,pain,and seroma formation after surgery.Therefore,accurate localization and measurement of the boundary of the MPO are crucial for selecting the optimal patch for inguinal hernia repair.AIM To compare the size of the MPO measured on three-dimensional multislice spiral computed tomography(CT)with that measured via laparoscopy and explore the relevant factors influencing the size of the MPO.METHODS Clinical data from 74 patients who underwent laparoscopic tension-free inguinal hernia repair at the General Surgery Department of the First Affiliated Hospital of Anhui University of Science and Technology between September 2022 and July 2024 were collected and analyzed retrospectively.Transabdominal preperitoneal was performed.Sixty-four males and 10 females,with an average age of 58.30±12.32 years,were included.The clinical data of the patients were collected.The boundary of the MPO was measured on three-dimensional CT images before surgery and then again during transabdominal preperitoneal.All the preoperative and intraoperative data were analyzed via paired t-tests.A t-test was used for comparisons of age,body mass index,and sex between the groups.In the comparative analysis,a P value less than 0.05 indicated a significant difference.RESULTS The boundaries of the MPO on 3-dimensional CT images measured 7.05±0.47 cm and 6.27±0.61 cm,and the area of the MPO was 19.54±3.33 cm^(2).The boundaries of the MPO during surgery were 7.18±0.51 cm and 6.17±0.40 cm.The errors were not statistically significant.However,the intraoperative BD(the width of the MPO,P=0.024,P<0.05)and preoperative AC(the length of the MPO,P=0.045,P<0.05)significantly differed according to sex.The AC and BD measurements before and during surgery were not significantly different according to age,body mass index,hernia side or hernia type(P>0.05).CONCLUSION The application of this technology can aid in determining the most appropriate dissection range and patch size.
基金Supported by the National Natural Science Foundation of China,No.82101985.
文摘BACKGROUND Gastric schwannoma(GS)is often misdiagnosed as gastrointestinal stromal tumors due to the high incidence of the latter.However,these two types differ significantly in pathology and biological behavior.AIM To evaluate the computed tomography characteristics of GS and provide insights into its accurate diagnosis.METHODS Twenty-three cases of GS confirmed between January 2011 and December 2023 were assessed clinically and radiologically.Imaging characteristics,including tumor location,size,contour,ulceration,growth pattern,enhancement degree and pattern,cystic change,calcification,and perigastric lymph nodes(PLNs),were reviewed by two experienced radiologists.RESULTS Our sample included 18 females and 5 males,with a median age of 54.7 years.A total of 39.1%of cases were asymptomatic.GSs appeared as oval and well-defined submucosal tumors,with exophytic(43.5%)or mixed(endoluminal+exophytic;43.5%)growth patterns.The tumors were primarily located in the gastric body(78.3%).Ulcerations were observed in 8 cases(34.5%),and PLNs were observed in 15 cases(65%).The average degree of enhancement was 48.3 Hounsfield units.Twenty cases(87%)showed peak enhancement in the delayed phase.Most GSs were homogeneous,while cystic change(13.0%)and calcification(17.4%)were rare.CONCLUSION GS predominantly showed gradual homogenous enhancement with peak enhancement in the delayed phase.PLNs around GS are helpful in differentiating GS from other gastric submucosal tumors.
文摘BACKGROUND Effective management of liver abscess depends on timely drainage,which is influenced by the liquefaction degree.Identifying predictive factors is crucial for guiding clinical decisions.AIM To investigate the predictive factors of liver abscess liquefaction and develop a predictive model to guide optimal timing of percutaneous drainage.METHODS This retrospective study included 110 patients with pyogenic liver abscesses who underwent percutaneous catheter drainage.Patients were divided into a poor liquefaction group(n=28)and a well liquefaction group(n=82)based on the ratio of postoperative 24-hour drainage volume to abscess volume,using a cutoff value of 0.3.Clinical characteristics,laboratory indicators,and computed tomography imaging features were compared.A predictive model was constructed using logistic regression and evaluated using receiver operating characteristic curves and five-fold cross-validation.RESULTS Independent predictive factors for good liquefaction included the absence of diabetes[odds ratio(OR)=0.339,P=0.044],absence of pneumonia(OR=0.218,P=0.013),left-lobe abscess location(OR=4.293,P=0.041),cystic features(OR=5.104,P=0.025),and elevated preoperative serum alanine aminotransferase(ALT)levels(OR=1.013,P=0.041).The logistic regression model based on these factors demonstrated an area under the curve of 0.814,with a sensitivity of 90.24%and specificity of 67.86%.Five-fold cross-validation yielded an average accuracy of 83.61%and a kappa coefficient of 0.5209.CONCLUSION Pneumonia,diabetes,abscess location,abscess composition,and preoperative serum ALT levels are significant predictors of liver abscess liquefaction.The model can guide clinical decision-making.
文摘Computed tomography(CT)can inspect the internal structure of concrete with high resolution,but improving the accuracy of measurements remains a key challenge due to the reliance on complex image processing and significant manual intervention.This study aims to optimize CT scanning parameters to enhance the accuracy of measuring crack widths and rebar volumes in reinforced concrete.Nine sets of specimens,each with varying rebar diameters and concrete cover thicknesses,were scanned before and after corrosion using an Optima CT scanner,followed by three-dimensional reconstructions using Avizo software.The effects of threshold values and“Erosion”coefficients on measurement accuracy were evaluated.The results demonstrated that an optimal lower threshold of 2950,combined with an‘Erosion’coefficient of 6,effectively limits the measurement error of rebar volumes to within 1%.The optimal threshold for measuring crack widths was influenced by the crack width,rebar diameter,and concrete cover thickness.Additionally,an optimized formula for determining crack measurement thresholds was proposed.This study significantly improves the accuracy of CT-based non-destructive testing(NDT)techniques,providing valuable insights for structural health monitoring(SHM).
文摘BACKGROUND Migraine has been proposed as a potential contributing factor to ischemic complications involving the retina and optic nerve.Ophthalmic disorders connected with migraine encompass occlusions of the branch and central retinal arteries and veins,alongside anterior and posterior ischemic optic neuropathy.With the advent of optical coherence tomography angiography(OCTA),it is easy to identify these macular subclinical microvascular and structural changes.AIM To evaluate macular and peripapillary structural and microvasculature changes in patients with migraine with aura(MA),migraine without aura(MW),and healthy control(HC)participants using OCTA.METHODS In this observational cross-sectional study,we studied a total of 100 eyes:(1)32 eyes of 16 patients with MA;(2)36 eyes of 18 patients with MW,recruited based on the International Classification of Headache Disorders;and(3)32 eyes of 16 age and sex-matched healthy participants.Foveal flux,foveal avascular zone(FAZ),peripapillary flux obtained from OCTA,and foveal and peripapillary ganglion cell layer(GCL)thickness calculated via optical coherence tomography were compared among the groups.RESULTS The mean FAZ area measured in patients with MA and MW was significantly larger than that in the control participants(P=0.002).However,there was no significant difference between the FAZ of the MA and MW groups.Macular perfusion in the superficial capillary plexus in patients with MA was significantly lower compared to MW(P=0.0018)and HCs(P=0.002).There was also significant thinning of the GCL in patients with MA and MW(P=0.001)compared to HCs.However,there was no significant difference in temporal GCL thickness between the MA and MW groups.CONCLUSION Significant changes have been found in structural and microvascular parameters in patients with migraines compared with HCs.OCTA can serve as a valuable non-invasive imaging technique for identifying microcirculatory disturbances,aiding in better understanding the pathogenesis of different types of migraine and establishing their link with other ischemic retinal and systemic pathologies.
